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I've glued up 2 rods with the new Aerodux resorcinol glue and I want to give the list a brief report on my experiences. This is a two-part LIQUID resorcinol glue...both the resin and hardener are liquid. That was the main attraction of the glue for me, to get the strength of resorcinol without the walnut flour filler. The resin appears the same as what we are used to, while the hardener is a dark brown goo about the consistency of molasses. A secondary benefit is that it cures at any temp above 50F which means I can leave everything in the basement shop even in winter. Aerodux is a product of Britain so it is possible that some of our builders from that side of the pond are familiar with it. It is imported into the US by Custom Pak, and they list two formulations on their website, a Medium and a Fast cure. (A web search indicated that there is also a Slow cure which apparently Custom Pak chose not to import.) These are available in gallons for about $160. Since I didn't need a gallon, I resisted the urge to buy it until I found it on Aircraft Spruce's website, in quart kits, for $65. When I received it, I was pleasantly surprised to have a quart of each, hardener and resin. (I was expecting a quart total.) The cans were clearly marked as being packaged by Custom Pak. The hardener had an "F" which I guessed meant it was the "Fast" cure formulation. I was hoping for the Medium cure but there was no choice or indication on the Aircraft Spruce page. There was no data sheet with the glue. I emailed Custom Pak to see if they would fax me one but they did not answer. I have not pursued this yet. The Custom Pak web site says the shelf life is 1 year at 70F and something I read implies its considerably longer at lower temps. I mixed the glue by weight and applied it with a tooth brush as I normally do. The mixed glue is fairly thick but spreads thinly. For the second rod I added 10 percent denatured alcohol by weight to make it a little thinner. The glue does set up fairly fast. After binding you have a few minutes to straighten, but just a few, before things stop moving. If you like taking a long time to fiddle with the blank, this is not the glue for you. It would be a service to the rodbuilding community if we could get access to this glue in the Medium, or even better, the Slow cure formulations. The resulting glue lines are still the characteristic resorcinol plum brown, but they seem thinner and less noticeable at this early stage than ordinary resorcinol glue lines. We will see what happens after a couple years. Summary: Advantages
Disadvantages
I believe someone came up with a formula to "bleach" the color out of Resorcinol glue, but I also think I heard that the effect was not permanent for some reason. Would any of you know of further experiments to get rid of those damn, purple railroad tracks? Probably, if it weren't for the color, ALL of us would be using the glue. Where are all those chemical engineers when we really need them? (Bill Harms) That was in the Garrison book. Hoagy said you can add universal pigments (I forget which, I think white and mustard) to the glue and it will turn it tan, but if you have to heat straighten, it will turn pink where it was heated. Sounds like more bother than it's worth, I'll just stick to Epon. (John Channer) I've been convinced for sometime now that there has to be a way to deal with the purple color that's more permanent. Maybe we just to need to find a chemist and convince him somehow that its worth the effort. (Bill Walters)
I'm wondering if that Resorcinol can stand 350 for say ten minutes? Anyone with any experience there? Maybe 300? Do I dare? (John Silveira) It most certainly will. The only downside is that it will turn jet black. (Tom Smithwick) The heat treating process is done before gluing up the rod section. Most people do it before final planing, although some do it afterwards. Even if you are building nodeless, I think the heat treating is done before scarfing and gluing. The sequence I use - your milage may vary - is this:
To anyone interested in trying resorcinol, I'd suggest the British Aerodux liquid catalyst version. No powder to worry about. Its not cheap but available in quart kits from Aircraft Spruce, and seems to keep a long time (years) stored in the refrigerator. Working time is short, however. If you are used to epon, it might catch you by surprise. There might be other sources besides Aircraft Spruce now. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive) I have also used Aerodux for my last two rods with very satisfactory results - nice thin even glue lines! I used alcohol to thin the glue which could explain some additional soak in and it certainly makes it easier to paint on to the strips. But in my case at least there is no way that lines can be eliminated as the Aerodux is supplied with a fine filler in one of the notionally liquid components. This glue is also strictly a phenol formaldehyde and those more knowledgeable have commented in the past that it is not quite as strong as the pure version. It is however more than adequate! Strong smell and very unhealthy, make sure you are in a ventilated area, strangely I don't notice the smell when painting it on but when binding up by hand it can get a bit OTT. (Gary Marshall) PS: yes I can get zero glue lines but only by using epoxy! If you keep your glue pot in a bowl of ice and mix it right out of the fridge you get a longer working time. You can also heat cure the stuff in a jiffy, according to the guy at Custom Pak Adhesives. (Brian Creek) You learn something every day......... Where do you get Aerodux from over here (UK), how much is it £ and in what quantities is it sold in? I have never even heard of it. (Paul Blakley) I'm answering your first question as your web search has thrown up a few other points. the following link should take you to Skycraft. As the name suggests they supply spares and materials to Aero fanatics. Aerodux is a certified adhesive for wooden airframes. They also sell Aerolite but I don’t think this is a viable rodmaking adhesive. Of the other adhesives you have found, Cascophen is a type of resorcinol glue but has one liquid and one powdered component, it is available from most chandlers as it is used in boat making. Extramite is different this is what used to be called Cascamite and is (I think) a casein based glue. It is certainly not a resorcinol. It is supplied as a white powder and mixes with water to give a paste. It is decent strong stuff and I have used it for various jobs in the past but it sets up much too quick for my speed of assembly. I did try it once! If you try the Cascophen I would be interested to hear how you get on. (Gary Marshall) Cascophen is now sold as Extraphen and I have been using this for the last ten years plus. It's marketed by Humbrol as is Cascamite (now called Extramite). Since my posting to the list I have done a web search for Aerodux and this is very similar if not identical to Cascophen. You should note that the color of Cascophen (as is that of Aerodux) is brown and NOT the famed red/wine of a 'true' resorcinol. My last five rods have been bonded with some resorcinol that I imported from Tony Young (now off the list and on his way to a new life in NZ) and this glue leaves the famed red/wine glue lines. Cascamite was the adhesive used by the old rodbuilders e.g Hardy, Allcocks etc. during the late 50's and sixties. The problem with this being over the years the adhesive crystallizes and breaks down leading to a gradual delamination. Aerolite 308 (with GBPX hardener) is a very fine rodmaking adhesive (note I state 308 as 306 is totally unsuitable) and is used by Chapmans etc. The problem with this adhesive is that one has to buy the stuff in bulk and I know of a few UK rodbuilders who club together to get a batch mixed but it is very expensive for the amateur. Guess I am stuck with Cascophen (Extraphen). (Paul Blakley) That’s cleared it all up nicely! I was interested in your comments on glue usage from past UK makers. I had wondered what was used particularly as neither the Hardy nor the Allcocks rods that I have show glue lines whereas the Sharpes one does. (Gary Marshall)
If I remember correctly, I read that there is a powdered die that you can add to resorcinol to help eliminate the purple glue line. Also, I have never used resorcinol how ever my next rod will be will be with this glue. My question, If I flame my rods is the purple line still visible. (Denny Dennis) Not as visible, but it's still there. Another problem I've had with resorcinol is even after sanding the glue off, after varnishing and time somewhere a resorcinol stain shows up on the surface of the rod where I didn't get all of it off. I've heard others complain about this also, and don't know if there's a good solution. (Brian Creek) The glue showing up on the rod after the varnish was a problem this is what I did. First of all I stopped cleaning the glue from the blank with sand paper and stated using a file. Tricky but doable. Then I started examining close after first varnish. I have planned on sacrificing the first coat of varnish at times. (Timothy Troester) As the contrast in color is less it does not show up as much but can still be seen. From my perspective the fine lines look great on brown toned or flamed rods but not so on blond rods. This is however purely subjective! With the Aerodux I use the glue line is a plum/brown color perhaps the pure resorcinol is more distinctly purple? (Gary Marshall) One solution I've heard of, but never tried (and I think this is the one listed in Garrison), is to add powdered titanium white (paint) to the resorcinol to lighten it up. I have been told by another rodmaker who did try it, that after a few years the base color of the resorcinol bleeds thru, an eventually the glue lines turn dark. I actually like the way resorcinol looks on a flamed or ammonia toned rod, and it's the only glue I use for gluing up sections. (Chris Obuchowski) The pigment to use is as manufactured wholesale by the Tioxide (IE: Titanium Oxide) Company. based in the UK and about ten miles from my home! I believe Tioxide are the largest manufacturer in the world of this white pigment 'paint' additive. (Paul Blakley)
I have never used resorcinol before but I have some that Todd gave me to try out and I want to use it on the 2 rods I have ready to glue up. There was some talk about the mixture for this. What is the best formula that people are using? I know it is not the same as on the cans. (Bret Reiter) I've used resorcinol on dozens of rods with excellent results every time. I mix by volume, and use plastic disposable picnic teaspoons. It's a ratio of 3:4 (I can't offhand remember which is which, but it says which on the can), with one part denatured alcohol. With the powder, it's important to level the measure with a flat object (scrape the flat edge of a scrap of cane over the top of the spoon - just like if you're baking a cake. Some folks are careful about sifting the powder, but to tell the truth, I don't bother anymore, and haven't had any problems with gaps or glue lines. (Chris Obuchowski) Wear gloves. It stains and is narsty! I wear goggles when I glue with it, but that's just me. (Brian Creek)
I just finished gluing up a blank using Resorcinol glue for the first time. After 24 hours I have it out of the string and sanded. How long should I wait before beginning to remove the slight twist I ended up with on this one? How much heat will this glue tolerate in the straightening process? Searching the archives tells me that the blank will continue to cure and get a lot harder for possibly a week. Somewhere there must be an optimal time to do this. (Steve Shelton) I don't think 24 hours is quite long enough. you will have to be gentle with it. I would wait a couple more days. when it is dry the timber of the sound you hear when you run you hand over the section will sound different than when yet damp. I discovered this right off so you will be able to distinguish this also. then again if you have sanded off the glue you might not be able to distinguish the difference, I suppose. I would wait a couple more days. you can straighten out out twists after weeks. I have done it. (Timothy Troester) Resorcinol is very tolerant to heat have no fears here. As for time I usually leave my blanks in string for three weeks before continuing with the process but I have a friend who is happy to continue within a few days of gluing up. (Paul Blakley)
My reading of the Garrison (Carmichael's) rationale for the appearance of the purple glue lines was that they were due to the color actually 'soaking into' the bamboo at the very thin edges at the junctions of the splines. The question in this time frame, is where is Borden's resorcinol glue available if someone does want to use it? (Vince Brannick) This is an interesting observation about the purple color being due to the glue sinking into the cane. The Orvis rods, because they are/were impregnated with Bakelite may not have had the same amount of absorption thus limiting the purple color at the glue lines. Mine is also a very dark brown rod so this may also have contributed to the color difference. Wonder if anyone who uses resorcinol has used it on darkly flamed cane and/or on impregnated rods and seen any color variations as a result? (Larry Puckett) Borden is now doing business under the name Hexion (same Columbus, OH address) and seems to market adhesives under the Hexion, Borden and Casco brand names. The Cascophen PRF are the phenol resorcinol resins; there are several. You can get Cascophen PRF in small quantities in the US from Aircraft Spruce. You can also get Aerodux resorcinol. It is expensive but mine has stayed good a long time (years) kept in the refrigerator. Its amazing what you can get in a few minutes with Google. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive) Thanks for the web addresses. The original Borden's resorcinol glue available, was made in the Borden plant in Bainbridge, NY, but at some 'point in time,' it was discontinued, and subsequent inquiries, generated replies from the personnel at the plant, indicated no knowledge of the product. I think 'Weldwood' at some time also made the same or a similar product. (Vince Brannick) As I posted yesterday, DAP Weldwood still makes resorcinol, it's available from several sources. (Neil Savage) And it's good stuff. Can be easily mixed by volume, and thinned with denatured alcohol. (Chris Obuchowski)
I’m looking for info about Resorcinol glue, I came across this web site for aircraft building supplies. Aircraft Spruce and Specialty Co. I thought it was interesting all the different offerings they have for adhesives! When I was starting out making rods, I had a boss that was into home built aircraft. He had just finished building a "Two Holer" (Tony), and he gave me some left over T-88 adhesive. I really liked it, but it didn't seem too popular with the rodmaking community. So, I went with Nyatex and Epon. I did make several rods with it and they are still holding up well. I get real nervous when it comes to heat straightening rod sections, no matter what adhesive I use! I still use the T-88 for cork rings, because I like the extended working time, color, and thin glue lines in the cork handle. (David Dziadosz)
Can anyone tell me of a source for resorcinol glue that would be from a fresh batch....that has not exceeded the shelf life? The only product that I have found locally is about five years old. (Larry Fraysier) I think you would be safe with Wicks Aircraft, or Aircraft Spruce, or a big boat building outfit like Jamestown Distributors. All have web sites. (Tom Smithwick) Sometimes you can find resorcinol at boating supply stores which has turned over more recently than at most hardware stores. Look online for Aerodux 500. There appear to be some U.S. suppliers. Its kinda pricey unless you can find small quantities, but its worth it, IMHO. FWIW I tested some really old DAP resorcinol I had on the basement shelves for at least 10 years. It seemed fine to me. But I trust Aerodux more I guess. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive) Why not go right to the source. http://www.cpadhesives.com (1-800-454-4583) Ask for the rodmakers pack. (Timothy Troester) Try McMaster-Carr. I've gotten it from them in the past and they were selling it in pint cans at the time. (Brian Smith)
If I use resorcinol on a blond blank, will the glue stain (discolor) the flats? I assume not, but I've never tried it. I don't mind the purple seams. I just don't want purple stains all over the flats. (David Bolin) You should scrap/sand all of the glue off the flats. No worries with it staining. (Todd Talsma) Sand/scrape or I use a file. (Timothy Troester) Depends on who you are. Everett Garrison and Bill Phillipson didn't have any problems with it, but H-I and South Bend either couldn't get it off or couldn't be bothered with it and theirs were flamed. (John Channer)
I was thinking the other day about glue entering the fibers of cane. I read somewhere that Resorcinol glues actually go into the power fibers 0.002>0.003" resulting in glue lines. Is this true of other glues? And if the glue does really go into the fibers, does anyone take this into account in the taper? I know from sad experience that glues that enter wood fibers results in stains applied later not entering the wood unless the glue is removed entirely. Would a similar glue result diminish the ability of the cane to accept finishes. Or are all finishes essentially "top" coats. (Don Anderson) Varnish and polyurethane are top coats, pure tung oil and linseed oil soak into wood, but I question if they do the same or at least to the same extent in bamboo, it is so dense. Oil based stains aren't effective on bamboo, so I doubt there is any harm to any finish from whatever glue you choose to use. I've refinished plenty of cheap old rods that had glue residue left on the surface under the original finish, as far as I could tell there wasn't any worse finish failure in those areas than anywhere else. (John Channer) Resorcinol thinned with alcohol does penetrate into the bamboo fibers, but only at the cut ends (think of thin glass straws and capillary action). The glue does darken with age, and so glue lines do look like they "grow" over time. I don't know about the other adhesives (the only one I use other than resorcinol is URAC, and that far less frequently). Since most of the others are neutrally colored, it'd be hard to tell if they do the same (though the epoxies all seem quite a bit thicker than resorcinol). (Chris Obuchowski) Wolfram Schott covers this in his "Bamboo Under the Microscope" which can be downloaded from the Power Fibers site. Schott also says Garrison's dilution and penetration figures are not accurate. (Ralph Moon) My thanx for the pointers @ the download from Power Fibers. Good stuff there. Read both of the downloads - Schott makes some enlightening observations based on his test results. Particularly liked the observations on planing Vs milling + heat treating regimes. Looks like resorcinol is the only glue that can be "seen". That is too bad. Would by great to see if other glues also "went into" the fibers. (Don Anderson) Given that resorcinol is the only colored adhesive, the thought occurred to me to stain the adhesives with oil based "paint" stains and see if one could learn anything. This would assume the stain would not preferentially migrate to the fibers. It is a good bet the oil based stains would not, at least some of them. You could likely distinguish the glue line anyway. (Dave Burley) Did an "experiment" rod about 8 years ago that I did a lot of things to:
And on and on. Thing learned - don't use flour catalyst for Urac. Dies soaked into seam. All in all, the stains worked poorly on rod shaft - blotchy - may have been problem with glue not totally removed. (Don Anderson)
At SRG this year I picked up some resorcinol glue to try. Thanks David! Though I haven't tried it yet, I'm curious. When gluing with Urac, many of us replace the powdered component with Ammonium Chloride. Has anyone tried to replace the powdered component of Resorcinol? A little research makes me think the powdered component is formaldehyde, but I'm not sure. College chemistry was a third of a century ago. (Harry Boyd) The active ingredient is paraformaldehyde. I tried it and it works. I haven't tried it on a rod though. I can send you some paraformaldehyde if you want to experiment. (Al Baldauski) I hate to bring bad news to resorcinol users but... I recently spoke to the DAP folks and was told that they plan to discontinue production of Resorcinal. I use DAP Weldwood plastic resin. Please check on your own, but that was what I was told. (Doug Hall) Search the classic fly rod forum - dap discontinued it, but it's still available through another distributor: DAP products and Borden chemicals no longer produce the stuff. Chempoint is now the US manufacturer and distributor for volumes of 5 gallons and greater. For small quantities, Aircraft Spruce is the only US distributor dealing in small quantities. They sell in pints, quarts and gallons. The have distribution centers on both coasts. They can be reached at 800-861-3192, or at aircraftspruce.com. They package the glue as Cascophen Resorcinol. It still comes with the powdered filler/catalyst in one can and the liquid resin in the other. I have been informed by Chempoint that Aircraft Spruce buys from them regularly so that shelf life is not an issue. Refrigerating the liquid will lengthen the shelf life. Harry that is a great glue you will like it. The Garrison formula works really well. (John Rupp) I'm not likely to change from Urac, but thought the Resorcinol might be fun to play with and let me know whether or not I have done a good job in my planing. Thought I might glue this current rod for a customer with it, but chickened out and used the Urac again tonight. With a little over 100 rods glued with Urac I have a good idea on how the rods made with it will perform. Maybe if I get some good feedback on how to eliminate the powder -- and thus much of the resulting increase in rod diameter across the flats -- I'll try it on a personal rod. (Harry Boyd) If in fact the catalyst is Paraformaldehyde (and that makes chemical sense). Please be aware of the Material Safety Data Sheet on this: http://www.sciencelab.com/msds.php?msdsId=9927382 an extraction from this sheet says: "Potential Acute Health Effects: Very hazardous in case of skin contact (irritant), of eye contact (irritant). Hazardous in case of skin contact (sensitizer), of ingestion, of inhalation. Slightly hazardous in case of skin contact (corrosive), of eye contact (corrosive). The amount of tissue damage depends on length of contact. Eye contact can result in corneal damage or blindness. Skin contact can produce inflammation and blistering. Inhalation of dust will produce irritation to gastro-intestinal or respiratory tract, characterized by burning, sneezing and coughing. Severe over-exposure can produce lung damage, choking, unconsciousness or death. Inflammation of the eye is characterized by redness, watering, and itching. Skin inflammation is characterized by itching, scaling, reddening, or, occasionally, blistering. Potential Chronic Health Effects: Slightly hazardous in case of skin contact (sensitizer). CARCINOGENIC EFFECTS: Not available. MUTAGENIC EFFECTS: Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance is toxic to mucous membranes. Repeated or prolonged exposure to the substance can produce target organs damage. Repeated exposure of the eyes to a low level of dust can produce eye irritation. Repeated skin exposure can produce local skin destruction, or dermatitis. Repeated inhalation of dust can produce varying degree of respiratory irritation or lung damage. Repeated exposure to a highly toxic material may produce general deterioration of health by an accumulation in one or many human organs". Paraformaldehyde decomposes to formaldehyde which is carcinogenic. I would not use this and think this explains why this product is being withdrawn. (Dave Burley) Dave I think the reason Dap isn't selling it any more is economic reasons not chemical reasons. Urac has a similar MSDS. It sounds worse than it is. Proper PPE (respirator, gloves, long sleeved shirt, safety glasses) plus proper material handling, storage, and disposal substantially mitigate the exposure risks below. Even just gloves and safety glasses make a huge difference. Denatured alcohol, acetone, and krazy glue all have the same health risk rating as paraformaldehyde (2). (John Rupp) I use this stuff in the lab occasionally. I always use a fume hood. Also watch out for drafts when handling the powder. That's how you get an eyeful or a snoot full. (Doug Easton) Here is the direct link to alternate resorcinol supplier. Reading this link seems to confirm it's a paraformaldehyde kicker, not sure that is as easy to come by, or as desirable to have on hand as, ammonium carbonate (that's the kicker for Urac right?) (John Rupp) You can order resorcinol from Custom-Pac. It can be ordered in pints or quarts and it is fresh. (Timothy Troester) Checking out CP Adhesives. I can only find they presently carry their resorcinol kits in single gallons (i.e., a 2-gallon kit for $115.00), 5 gallons and 55 gallons (now that's a lot o' goo). Nothing smaller that I can see. (Bob Brockett) Call them. They have always made the small amounts available as a courtesy to rodmakers. (Timothy Troester) It always amazes me how some companies offer such a remarkable service to small buyers. This is germane to nothing at all, but I buy my Epon here in Australia from a company in Sydney called Adhesive Engineering; they are big suppliers to industry, and while they think in terms of hundreds of liters of product, they will still take the time and trouble to re-pack, label and post small (liter) quantities to people like rodmakers and bow makers. They charge a reasonable price for the product, so it cannot have anything much to do with bottom line. Thank Heavens that in our voracious and greedy modern commercial culture we still have a few companies like these who still take a bit of trouble. (Peter McKean) They're just hoping that when you go "Big Time", making 50,000 rods a year you remember their helpfulness and still buy their product. (Al Baldauski) I just found out Aircraft Spruce ships worldwide via DHL, so I can get the stuff down here in Chile. Peter I'm a bit jealous, unfortunately I don't have the same kind of customer service down here in Chile - I can buy the glue locally but I have to buy it in 5 gallon containers! They basically told me no when asking for a smaller package. Customer service in Chile is nothing like the US or apparently Australia. There's always an excuse for why something is out of stock or didn't perform as advertised, and if you want to return something - forget it. Exchanges are grudgingly allowed only in some cases. The Spanish word they use for the process is "change" (cambiar) not "return" (devolver) which gives a lot of insight on the way the situation is thought about here. (John Rupp) I think that is a ONE-gallon amount for $115. Given the shelf life of the stuff, this might be a good candidate for a group-buy. 8 guys going in on a gallon should knock the cost down to under $20 for a pint - figuring in the product & shipping, repacking containers, and shipping back out. But then again, as John Rupp mentioned a few days ago, AircraftSpruce.com sell it in pints for $19.90!!! (Mike Biondo) Just emailed them to see if that's a kit of a gallon each of the resin & catalyst, or 1/2 gallon of each for a gallon total. Let you know what they say, since I'm not clear looking at their site listing again. For myself, I did just purchase a pint kit from Aircraft Spruce, so I'm okay for now. Shipping isn't cheap on this stuff. But, doesn't hurt, as we've seen, to always have back-up sources. Now, if we could just find some 4-year-old genius chemist to permanently lighten (or change) the cured color of this stuff, we'd all be in rodmaker heaven. (Bob Brockett) As a further newbie inquiry, can anyone compare/contrast the uses of URAC and resorcinol? Saw a terrific attached article a while back on the list talking about how well resorcinol holds up in marine laminate applications, compared to epoxy, when exposed to UV and salt water. Also note tests conducted by a list member, whose name I apologize for not recalling immediately, suggesting URAC rods are slightly stiffer than those glued with other adhesives. But claret-colored resin aside, is there any performance reason anyone is familiar with to choose one over the other. (Steve Yasgur) Here's what I got back: Bob: received your question about the amount included in the gallon kit of resorcinol. We call it that because we are selling you a full gallon of the liquid resin (9#), plus the appropriate amount of powder hardener to catalyze -that gallon, which = 1.8. The total amount of mixed glue you can make is 11.8#. Let me know if any further questions. Kind regards, -- I know this study by one Larry Pardey has appeared here before and is linked on the CP Adhesives site, but looking it over again I notice now where he makes the distinction (pg 18) between summer-grade resorcinol (Weldwood, DAP, Borden) and winter-grade (Cascophen, the same type, apparently, sold by Aircraft Spruce; just bought some myself, but due to hand surgery will have to wait to try). Winter-grade, according to Pardey, is superior with (go figure) lower curing temps, better gap-filling, and less worry over clamping pressure. If I'm reading this right. Can anyone speak to this? (Bob Brockett) It seems to have a lot going for it - 60 minute pot life at 86F seems very good to me, the dap stuff I used would set up after 20 or 25 depending on how hot it was. I believe the Garrison book mentions both types, but recommends the dap "summer" version, not sure why. Need to go back and read that. (John Rupp)
Here is where I have sourced the Resorcinal. As a courtesy (BE NICE!) they will supply it to us in quart kits. (Timothy Troester)
Well, I've never used Resorcinol, and don't know nothing about its color. But most of us, ahem, guys are wired to not give much hoot about "colors" aren't we? I probably missed most of this conversation anyway, like most guys when talking goes on they're not too interested in. It blends into the fall foliage. I still can't figure out what colors puce, or sea foam, or unicorn's hair are. I learnt my colors in Kindergarten. Whatever 8 colors they had in that crayon box, are the only true ones. See? Green is green, and Pantone Golf Green 18-5642 TCX don't tell me no different. So if it ain't exactly them, or if it ain't exactly purple, it's purplish. But then my ape index, my Cro-magnon skull measurement, hasn't improved far enough with age to suit most people, probably. My knuckles still hang just past my knees. And my brow gets heavier when I ponder the color puce. Just so no one mistakes my color names for wrong colors, they are from that other coloring savant system, Crayola's red, orange, yellow, green, blue, purple, brown and black, and has been since 1903 or so. Now let’s talk about colors of flamed bamboo in order of darker to lighter. There's black, almost black, not quite almost black, red pine rot, almond skin, toasted (not burnt) marshmellow, hazed mustard, honey, clover honey, maple breeze, dirty dishwater blond, blond, anemic blond, and albino yellow. Any questions? Now for thread colors.... (Sam Nielson) If you look at this link of Crayola colours it may help:
You'll see purple mt majesty, that's not resorcinol. Another one that's not quite right but close enough for this level of explanation is brick red. (Tony Young) Not a very good picture, but somewhat illustrative.
The rod at the top was glued up 3 years ago with the Cascophen. It shows the black glue line, but I chose the particular spot on the shaft because there is an area where I left a trace of glue on the shaft before varnishing. That is one of the joys of resourcinol. They don’t show right away, but show up a couple months later. Note that the claret color is in evidence in the very thin traces. If you think you are seeing a twist, you are right. It’s a spiral rod. The lower rod was glued up 30 years ago. You can’t easily tell, but the claret color persists in the glue lines. There are some splotches on that rod, too. They look like exactly the same color as the spots on the newer rod. Years ago, I spliced a few strips before planing, and later heat treated them. The resorcinol in the splices turned jet black, but was still strong. (Tom Smithwick) Yep, this is about as you'd expect with resorcinol. (Tony Young) Those who attended the Catskill Gathering may have heard Jim Krul saying that he would like to see a Garrison taper rod built on the Garrison equipment now in the museum. I like the idea and would like to see it look as authentic as possible. I don’t think we will have much problem coming up with the components, but one thing that may prove difficult is to reproduce the true purple glue lines of the original resorcinol formula. This can be observed on Mr Garrisons rods built after the late 30’s, many Phillipson rods, Gillums later work, etc. By the time I started building rods in the mid 1980’s, it was already a new formula that was still an excellent glue, but the color was now a dark reddish brown, sort of a claret wine type thing. The latest stuff I have dries almost pure black. I admit I’m probably the only person in the world nostalgic for the true purple glue line. (can someone post a photo of such a rod?)Anyway, if the old formula is produced anywhere in the world, I would like to hear about it. I have a feeling that is highly unlikely. Failing that:
In either case, the pigment would need to be colorfast over time, and not affect bond strength. (Tom Smithwick) I used the resorcinol glue several times, produced by the company Cecchi in Livorno (Italy), the color is not purple but a very dark red almost brown.I think that the composition is changed a lot in recent years. (Alberto Poratelli) A couple of drops of TransTint dye should do the trick. I've used it to color cane with great results. (Lee Gomolchak) This purple colour thing has come up many times over the years on this list. I can very vaguely remember once seeing a wooden mast made with resorcinol that was not quite claret but was still in the red/brown spectrum but every glue line I've ever seen that was resorcinol going from boats to lately the plywood used on a Vampire jet hangered at the place I work was claret as per Mallard and claret sort of thing. Peter McKean, do you remember the colour of the Phillipson Smuggler? Was it redish or purple? I sort of remember it being a little different to maroon but maybe not. Never having seen a Garrison rod I have to wonder if the glue ever really was purple or did Garrison just think claret/maroon was purple? (Tony Young) You are quite correct, Tony - the glue lines were quite dark, but quite clearly dark maroon rather than than what I would call purple. In the south of Tasmania there is a walk in the bush overlooking a river, and the shelter sheds along the way were made and donated by the Tasmanian Wooden Boat School; all the main uprights are made of laminated woods (various), and their glue lines are noticeably more purple. This is especially obvious where the students have here and there smeared a bit on the exposed surfaces, especially where they have used pine. (Peter McKean) Though I have never glued up a rod with resorcinol, I can assure you the stuff from long ago was purple!!!! Years and years ago I was a cabinetmaker and millworker. We specialized in reproducing custom redwood windows, doors, sash and other millwork for victorian homes. We only used resorcinol, and although the purple stains have long gone away from my hands and arms, I do still have my coveralls which are covered with purple globs and stains!!! (Paul McRoberts) Very strange. The Vampire jet was built in 1948, these old boats I used to work on were all well over 50 years old. Pictures I've seen of Mosquito aircraft have very dark gluelines. I took a rod with me to Grayling in 2002 I think that was made with resorcinol. Somebody looked at it and said something like the glues nice but too bad about the purple colour. It was then that I had to stop and wonder if people are calling something purple that I'd call claret but I'm just guessing. I wonder why the colour would be different in the US? Is the colour on your overalls at the violet or the red end of the spectrum? None of this really matters of course but it's a question that's rattled around for a long time and if somebody is going to the trouble of replicating the colour it does matter that the colour is established.
I'd place resorcinol at #4695 and consider the colour purple to be around #511. (Tony Young) I'd place resorcinol at #4695 and consider the colour purple to be around #511. I agree with you Tony. The Weldwood stuff I have used since I started in the mid 1980’s has looked like #4695. Weldwood does not make it any more. If I had to define purple, I would also pick #511, however, what I remember on the Garrisons and Phillipsons is lighter, about like #512. I am now using the Cascophen brand, bought from the experimental aircraft companies, who take expiration dates seriously. It basically turns black almost immediately. I’ll try to post some pictures later today, but I don’t own one of the rods with the true purple color. It looks like the true purple stuff is not available anywhere. I will probably have to try dying a lighter colored glue, as others have suggested. I mostly use epoxy these days, because of the long work time, long shelf life, and reliability. For harsh conditions, however, I believe resorcinol to be the best choice, as it always has been. I don’t know what caused the change from purple to claret. It may have been a change of manufacturers, and it may have actually been an improvement. I suspect the long nose of nanny government in the recent change, but that may just be the paranoia of a grumpy old SOB, too. (Tom Smithwick) I'm glad to read that the glue Garrison used was close to #511 if only because it lays to rest something that has always puzzled me about what I read compared to what I've always seen. Personally, I think resorcinol is the best glue you can use though the others are so good that there's no point to my mind in debating things. Titebond is so good and easy to use and get that it's what I've ended up using anyhow. I did used to beat the drum for resorcinol before it became so hard to get other than from aircraft supplies simply because if you want a glue that simply never fails period it's the glue to use. I have a Driggs taper rod made nodeless using resorcinol that's over 15 years old. It's my go to rod, has been absolutely thrashed and was once use to fend off a tiger snake (I also ran backwards very quickly with not a single jot of sangfroid remaining), not a thing wrong with the rod. I have a Dickerson 7614 taper rod not fished quite as hard but same story. Considering the problems I had with nodeless rods using every other glue that's really saying something but the sentence in "the bible" about it being purple prob stopped a lot of people from even considering it and I tended to try to get to the bottom of what this purple thing was to the point that I was convinced that half the world was calling what I saw as claret purple. I know that if I didn't know from previous use that resorcinol is claret and not purple (these days at least) I'd have never considered it either. It is interesting though. I wonder if the purple was specific to Weldwood? It doesn't matter anymore, the glue's virtually unobtanium these days anyhow unless you really want it but it'd be nice to know after all this time. (Tony Young) One thing that will constantly bother us is our meanings for words. Reminds me of when I first started tying my pheasant tails with Uni-thread 6/0 “Claret” color more than 20 years ago. There are many different shades of claret, and it must have been confusing to a lot of people - now Uni calls it “Wine.” I prefer “Burgundy” myself… (Tom Vagell) Until about 10 years back I worked for a while with a mob that made polar fleece and Gore-tex mountaineering clothing. I don't know why I didn't think to relate the colour I've been trying to explain to the Pantone chart in the first place.
We certainly didn't order a 20-foot container of Gore-tex based on a colour described as basically royal blue but sort of skyish. We'd just say it was Pantone #5621 or whatever. (Tony Young) OK, until just recently almost all of my books were stored in the far left hand corner of a 40-foot container under everything including but not confined to outboard motors and chain saws, LF enlargers and SCUBA gear, life jackets, guitars and stuff in large bags I didn't look in but all safe in new 10 frame bee hive boxes. Most of the books are still there but a few have been rescued and with me now and one of them is A Masters Guide To Building A Bamboo Fly Rod by a guy called Carmichael, some of you may have a copy. Mine is the 2nd printing of 1995. I'm looking at page 88 last para and it's very interesting. It says in black and that off white paper to use Cascophen RS-224. What's more it says very clearly that this particular resorcinol is two part, a dark wine-coloured liquid and the catalyst. In the 6th para same page it goes on to say that some don't like the dark wine coloured glue line that is unavoidable if one uses phenolic resin glue. Later it says the dark colour is an important ingredient and can't be avoided. Para 7 recommends you use URAC 185 if you don't like the dark glue line. Now, I have to ask the question and I think you know what it is...Where does PURPLE come into it???? Clearly I'm not as mad as I thought I was going and my search for a non claret-coloured resorcinol can end. (Tony Young) What's more it says very clearly that this particular resorcinol is two part, a dark wine-coloured liquid and the catalyst. Good point, Tony. I checked the 1977 first edition, and the description is much the same. Whatever happened to the true purple color evidently preceded the publication of the book, and probably Mr Garrison’s passing, just a bit earlier. Evidently, he did not lose any sleep over it, and I guess I should not either. Makes sense, as Hoagy pretty clearly states that Mr. Garrison was more interested in the glue’s performance than its cosmetic appearance. (Tom Smithwick) My issue with this has always been one that if a person who has never seen it is told the glue line is purple when it is in fact not that person will continue to say and think resorcinol is purple which is what has been the case to date giving a completely different impression as to the appearance of the rods. Now considering we are RODMAKERS, the keepers of the keys as it were who concern ourselves with planing strips to within 0.001" and agonize over the colour of wraps on vintage rods and other details I should have thought that people would have been interested in knowing the true colour of the glue lines of Garrison's and other's rods rather than continue under a misunderstanding of such a basic thing but it seems I'm wrong. Perhaps if enough people begin calling Chinese Red Goldenrod everything will work out the same in the end. (Tony Young)
Just curious how much moisture content testing has been done on bamboo. While reading over the product bulletin for the Cascophen I ordered, I came across this. "Moisture content of wood is most important and should be from 8-16%, preferably within the 10-12% range". Anyone test the moisture content during a build? (John Smith) Is bamboo considered wood? does it have the same character as wood... just a question! (Michel Lajoie) Bamboo is not wood but is a "woody grass". Do the same "rules" apply for bamboo as they do wood when using the Cascophen? I don't know. My main question was really about moisture testing. I'm just curious if anyone has tested the moisture level in a raw culm versus a "dried" blank. (John Smith) I have measured moisture content by carefully weighing a sample, baking then re-weighing. I’ve determined that a typical culm, in MY basement, has about 6% moisture. By weighing again, after a long time, I’ve found the bamboo regains moisture to the tune of about 5%. So it never gets back all of what you’ve driven out. This has been confirmed by Wolfram Schott. He’s got two long articles about bamboo. Interesting reading. I’ve heard some guys say they either wipe their strips with a damp sponge or use a mist sprayer just before gluing with the likes of Cascophen. I’m guessing the trick is to NOT use too much water. (Al Baldauski) Kiln-dried lumber typically regains moisture, as does the wood in your guitar, home, etc. Usually the range is an Equilibrium Moisture content from 6-9&. Anything at 5% or under is considered excessively dry & liable to spontaneously combust. (Paul Julius)
Anybody using resorcinol? (Reed Guice (7/20/2016)) I use resorcinol. Pros are: 1. Very strong; I believe it makes a stiffer rod than epoxy or PVA glue, a hundred other things being equal. Cons are: 1. Short open time; have everything ready to go and pee before you mix it. I order from Aircraft Spruce; every time the brand & packaging changes but the product seems the same. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive) I use resorcinol, now labelled Cascophen, and like Frank buy it from Aircraft Spruce. While the open time is not as long as some glues, it is not as short as Titebond 3. The glue lines are a reminder that you need to have good technique. (Bill Lamberson) It's great glue! Completely waterproof like 100% waterproof, not that it really matters on a rod, absolutely will not fail once it's cured provided you've applied it right.
Basically, resorcinol is very strong and very durable. Epoxy is not a gap filling adhesive. The only time it should be used for gap filling is if additives are used like microballoons or fibers. Epoxy relies on a thin film to give its best bond strength. The thicker the film, the weaker the joint. It's gap filling compared to resorcinol which is like water by comparison. Epoxy is like honey. (Tony Young) That all depends on the epoxy and what it's used for. I've used epoxy that's as thin as water too, mainly laminating epoxies. (Mark Wendt) Epon is like honey though. So are most you use off the shelf. (Tony Young) A quick application of a heat gun turns it to near water. Really easy to control. (Ralph Tuttle) Ah, but the consistency can be controlled, even when the stuff is “normally” viscous. For my blanks, I happen to use UHU Endfest 300 Plus epoxy which, when initially mixed, is quite viscous. Warming the mixed epoxy (I use a heat gun) reduces its viscosity considerably. The stuff has a 11/2 hour working time and the warming (not hot) does not seem to affect that. I also use off-the-shelf 5-minute epoxy for various things and warming it also reduces the viscosity a lot, but does help it set up faster. (Tim Anderson) I hear what Tim & Mark are saying about epoxy being at its best without fillers but epon as it comes from the bottle and almost all other epoxies you'll see unless you have a supply from a place that deals with specialized laminates used to hold together in supersonic flight will have fillers and these don't have enough fillers to be a problem for our use or pretty much anybody else's use either. The only time fillers become a strength issue are when you have a lot of filler compared to the amount of glue such as when you're forming a fillet for filling huge gaps or fairing a surface. If you don't add fillers to Epon for eg you haven't harmed its strength. The best amount of glue to use on any job is the least amount that will work and fillers aren't glue so technically any filler is bad but let's get real. Epon for instance as it comes in the bottles works.As such, epon or most other epoxies as most people use them as recommended by the maker are relatively thick and fill gaps that thin glue won't. That's a big part of why epoxies have become so popular and have pretty much completely taken over from resorcinol for eg even though resorcinol is stronger and forms a better bond with the wood but which does not fill gaps at all and requires a good fit for the glue to work. (Tony Young) I tried thinning resorcinol once by heating the liquid part with a heat gun before mixing. Whatever fumes were given off it felt like a spike was being pounded in my forehead. Decided not to repeat that experiment. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive) Those "gaps" that are filled contribute nothing to the strength of the joint, and in fact weaken it. The thicker the film of adhesive in the joint (with epoxy) the weaker the joint. I'd suggest working on getting rid of the gaps rather than trying to use an adhesive to fill them. Epoxy by itself has little to no strength. As a test, pour a mixed batch onto a sheet of wax paper. Let it cure. Peel it off, then start flexing it. It will shortly break into two pieces. The chemical cure, the bonding to the matrix of the joint and thin film lines are what give epoxy joints the strength they have. Adding more epoxy to that joint only weakens the joint. Another reason I don't recommend folks "rough" up the cane when doing ferrule stations to give it "teeth" for the epoxy to grab onto. The best surface for a thin film epoxy joint is what the manufacturers call a "water-break" surface. Lightly scuffed, and water does not bead up but spreads out in a film. (Mark Wendt) True, it's better to eliminate the gaps but I have to ask, is it possible to have a gap big enough to weaken the epoxy that it fills on a rod? In any case. If the rod strips are made made to within 0.001" of each other which is the target, then you could use resorcinol and the glue line would be a whisper of a shadow of a vague hint of a dark line hardly noticeable at all and technically speaking stronger and possibly stiffer too than what is possible at all using epoxy no matter how thinly it's spread. (Tony Young) Dunno. I have seen some fairly wide glue lines on some rods though. Not knocking resorcinol at all. It's a very good adhesive. But comparing resorcinol and epoxy is like comparing apples and oranges. Both have different properties and are quite dissimilar. I would imagine however that the ultimate bond strength in a resorcinol adhered joint is gotten through the optimal adhesive thickness, much like epoxy. The properties of each though show that both are excellent adhesives for laminating. (Mark Wendt) I'm just saying that I doubt that it's even possible to make a rod with gaps so large that the voids that rodmaking recommended epoxy fills will weaken the rod to the degree that it'll fail and if it did fail that's a very good reason to consider using a different glue. And that while it's true that the least amount of any glue that bonds the work piece is the best amount to use, if strength of bond is the biggest issue don't use epoxy regardless of the quality of workmanship, use resorcinol because provided you apply it right and it's not difficult to do, it simply wont fail at all under any circumstances that you could subject a rod to short of complete destruction of the rod itself and even then, the sections will stick together. You can even boil the rod if the urge stuck you and the rod sections will stay bonded. But, absolute strength of the bond isn't the last word on the subject and it's because appearance matters as do personal choice of glues for any number of reasons. I just think the angst over whether or not epoxy does or doesn't fill gaps and if it's filling gaps weakens the bond is only true technically speaking and just isn't an issue on real life rods. Epoxy does fill the sort of gaps accepted by many rodmakers as does TBIII as does polysulphide glue as does Cascamite that I wrote of earlier and possibly also URAC or it's modern day incarnation, I don't know because I never tried it. These glues also hide the gaps because they're pretty neutral to the cane, but they aren't the strongest bond you can get, nor are they truly waterproof not that that's all that important. The glue that does it all apart from fill gaps and blend in with the cane is resorcinol, the question was what's it like for rodmaking and I would say it's the best if you don't mind the glueline and don't have gaps. (Tony Young) Thanks for your info on epoxies; after a lot of the voodoo stuff, your posts are like a breath of fresh air. (Peter McKean) Been working with epoxies for over 40 years from fiberglass/carbon fiber/kevlar layups, to making plug moulds, to laminating, to just about any use you can think of with the stuff. Epoxy seems like a simple thing to use, and for many things it is. But sometimes you gotta go through the manufacturer's literature on the stuff if you want the optimal use of it. Back when I was working with epoxy a lot, I had binders full of manufacturer's literature that spelled out surface prep, film thickness, drying times, heat cures and their temps, how much clamping pressure was needed, how much vacuum to hold and so forth. There are a lot of common misconceptions out there about epoxy. Problems arise because people don't take the time to read the literature, don't do the correct surface prep, or use the adhesive in an incorrect manner, such as expecting the adhesive to be gap filling when laminating. (Mark Wendt) That should have been low viscosity means it's not thick and it fills gaps effectively. (Tony Young) You can build up a surface with multiple coats of clear lacquer too. Doesn't mean it's considered a gap filling coating. It's the additives that make epoxy gap filling. And reduces the strength of the joint in a laminate. (Mark Wendt) Mark, we're talking rods here aren't we? All of what I described above was to say that properly filled epoxy will fill gaps and wont weaken enough when used for a rod to matter at all. As for not needing to perform a test, that may be true but if you did it you'd see that for a rod it makes zero difference to a rod as in fishing rod because the rod with the filled gaps won't break sooner than the ones without them. If it did why use epoxy when Titebond will do the job better by the sound of it? You can say it will because the specs say it's so, but it won't. The gaps are just too small to matter. It's a simple test. I don't have the glue, but you do. The part about 826 filling with no voids means it fills the gaps in the weave. That was a typo when I wrote it was thick. Should have been not thick. If the gaps between the weave are filled, then you have epoxy filling the weave gaps no? Non-filled woven material is material. Material that has the weave gaps filled with epoxy has structural strength, yes? When you fill the weave of glass on a deck you fill the weave with epoxy until it's full, typically takes about 3 goes to do it. One coat is weak, you can break it off with your hands, three is strong. Ask anybody who ever made a cedar strip canoe. You usually leave the weave just proud in a deck for a nonslip surface. The reason the epoxy was thick for the boats was because for that purpose that's what's required. That's why I said boats aren't JSF or Dreamlineres, the same reasoning can't be used regardless of the application. Epon comes in the state it comes in because the makers think it's the way to use it. Modify it if you like but as it's made at 20c It's about as viscous as honey at 20c. At 20c it fills gaps. It cures. It holds rods together. (Tony Young Mark, we're talking rods here aren't we? Yes, we are. A lamination process, with microscopic voids in the laminate material. Not a composite layup matrix. All of what I described above was to say that properly filled epoxy will fill gaps and won’t weaken enough when used for a rod to matter at all. All I'm saying is if you're relying on epoxy to fill gaps, you aren't getting the optimal joint. The thicker the film, the weaker the joint. If you did a destructive test on a rod section where the film thickness is optimal, versus a rod section that had a gap like a glue line, the section with the gap would fail before the section with no glue line. That's just plain physics and statics and strengths of materials and bonding agents. As for not needing to perform a test, that may be true but if you did it you'd see that for a rod it makes zero difference to a rod as in fishing rod because the rod with the filled gaps wont break sooner than the ones without them. If it did why use epoxy when Titebond will do the job better by the sound of it? Who said Titebond would do a better job? A proper epoxy joint will always be stronger than one made from alaphatic resin. You can say it will because the specs say it's so, but it won't. The gaps are just too small to matter. It's a simple test. I don't have the glue, but you do. The part about 826 filling with no voids means it fills the gaps in the weave. That was a typo when I wrote it was thick. Should have been not thick. If the gaps between the weave are filled, then you have epoxy filling the weave gaps no? Non-filled woven material is material. Material that has the weave gaps filled with epoxy has structural strength, yes? You could also achieve the smooth surface with multiple coats of clear lacquer. Do you consider lacquer a gap filling agent? Again, you are comparing apples and oranges between a composite matrix and a laminate matrix. Different materials, different strengths achieved. A coat of epoxy on a composite matrix, even the thinnest epoxy or surfactant will eventually build up. Does it give more strength to the matix? No. It just adds weight and eventually gives you a smooth surface to apply a coating to. When you fill the weave of glass on a deck you fill the weave with epoxy until it's full, typically takes about 3 goes to do it. One coat is weak, you can break it off with your hands, three is strong. Ask anybody who ever made a cedar strip canoe. You usually leave the weave just proud in a deck for a nonslip surface. It's the epoxy/fiber matrix that makes it strong. Try the same experiment by just putting three coats of epoxy on the deck with no fiberglass. The additional coats are being added more as a protectant for the matrix and as a surface for a coating. Don't forget, your matrix also includes the surface of the deck the fiberglass/epoxy is being put on. That then becomes part of the composite matrix too. Take that same fiberglass, lay it on wax paper, and add your three coats. When cured, peel it up. How much ya wanna bet you can break that composite apart with repeated flexing? Fiber composites get their best strength to weight ratio by using the minimal amount of the binder as they can. Take a peak at a premade carbon graphite strip. Those are made by vacuum clamping, squeezing out all excess epoxy binder. Very light, very strong. And they have smooth surfaces. The reason the epoxy was thick for the boats was because for that purpose that's what's required. That's why I said boats aren't JSF or Dreamlineres, the same reasoning can't be used regardless of the application. Epon comes in the state it comes in because the makers think it's the way to use it. Modify it if you like but as it's made at 20c It's about as viscous as honey at 20c. At 20c it fills gaps. It cures. It holds rods together. The Epon products we use come at that thickness. Their other products come either thicker or thinner, depending on what resin and hardener you are using. And you can thin the Epon to the consistency of water without terribly affection pot life by heating it. (Mark Wendt) I think you should try the experiment. Others have, and you may just be surprised.To make a difference to the strength of a lamination in the real world you're talking about gaps you could see through, I'm talking the kind of gaps you could reasonably expect in a rod. Makes no dif at all to the strength of the bond when we're talking fishing rods.My comment about Epon being the viscosity that it is at 20c is that somebody at Mr Epon's factory decided that that's a good workable viscosity at 20c and will work. Presumably that person knows what he's doing and at that thickness it fills gaps, cures and holds rods together. If you wish to alter things and use different hardeners you're free to do so, it says so in the specs, but it works as it is and it's quite thick. I'm not confusing composite and laminate. I'm making the point that in order that a matrix become a structural member the gaps within the weave must be filled. No lacquer won’t make it strong, we're not talking lacquer, we're talking epoxy. Also, I think we're in agreement re the epoxy filling the weave of the fabric. I did write that you fill the weave typically taking three coats to fill it to just under completely full and that one coat can be broken by hand. I've made carbon/foam kayaks using vacuum bagging, I'm aware of the process. It's because I've seen enough epoxy to 1) become sensitized to it and 2) know that you're applying technical details that are correct and need to be adhered to (get it) if you were building a Dreamliner where you'd stick to the specs or else but knowing that in the real world, "meat space" as it's now known apparently gaps of the size you'd find in a rod wont matter at all. Also, I'm not so sure that epoxy is stronger than PVA glues. In fact I'd refute that and I'm not the only one. PVA glue is stronger than you may think. So is UF. These guys have done tests comparing PVA and epoxy and also interestingly show tight, snug and loose fits. http://www.titebond.com/Libraries/News_Articles/HowStrongisYourGlue_FWW.sflb.ashx Yes, it's conducted by Mr Titebond, but you'd have to think it's pretty indicative and it is why I think you should do the test I've suggested yourself, I believe you'd find that the sections will fail at the same statistically equal point. Resorcinol is certainly stronger than all the glues, but it's not tested. Read the article but just in case you miss it, the loose fit was a gap of 1/64" and that's loose. As a woodworker you'd be a bit annoyed with yourself if you made a joint that bad. That is a joint that pretty much only the glue is in contact with the wood, so the glue is in effect a fillet, certainly not the bound fit of a rod blank during a glue up. 1/64" or so is pretty close to the sort of gaps you see on some rods as it happens which makes this even more interesting. If you look at the results you'll see that in some cases including epoxy a tight fit was sometimes best, sometimes a loose fit and others snug. In the case of maple there was hardly any dif at all between the three fits. That's my point about you not being able to use one glue regime and apply it to all applications and the reason tests are worth performing. Any gaps in the rod are tiny, vanishingly close to non-existent compared to what you see in wood projects. Even a tight fitting tenon has saw marks that are bigger, and the mortise has more chisel marks than the gaps found on even the most gappy rod. Any gaps that can be filled by epoxy or PVA or whatever in a rod make no dif to the strength of the rod. But don't believe me, read the article. (Tony Young) First of all, though I do have the epoxy, I don't have the precision measurement equipment and test stands required to precisely measure the effects of a thin film thickness vs a thick film thickness relating to the strength of the joint. However, these guys did, and they back up everything I say: *It's a pdf of experiments of film thicknesses vs joint strength, starting at .1 mm and thicker. A quote from the bottom paragraph on page 15: "There is an influence of bond-line thickness under shear and tension/shear loads on the plateau values, with a much larger influence for tensile loading. In all the cases examined here lower plateau values were obtained for thicker joints. The failure mode was cohesive for tensile loading but adhesive for shear and tension/shear loads. Failure stresses are higher in tension than in shear, but failure strains are much larger in shear. Figure 18 shows the deformation of a joint during pure shear loading before failure, the shear bands are clearly visible. It is interesting to note that the tensile strengths obtained on film samples are like the mean tensile stress at failure of the thickest joints, whereas considerably higher strengths were obtained on adhesive samples with thin bond-lines." You can stick with your old wives’ tales and marketing hype. I'll stick with the engineer’s recommendations and the scientists who actually test these things with accurate and precise measuring equipment and the test stands that give repeating results. (Mark Wendt) But if you keep reading past page 15 and onto the top of page 17 it continues to conclude that glue thickness is OK up to 0.8mm (0.033") for shear which is what we're mainly interested in and < 0.6mm for tension (0.024"). It even states that in the abstract. 0.8mm is a pretty thick sort of glue line you know. So is 0.5mm. The link I recommend if you read it was not a marking hype. It was done and tested in a way that you should approve of and published in Finewoodworking. It's just to Titebond's advantage so they have it on their site. Did you read the article??? You're telling me that they did not properly test the pieces using good methodology with accurate testing equipment? To repeat the conclusion on page 17 of the report you sent the link to, those tests you're talking about were conducted on 2017 Al and in the meaty bit on page 17 recommend glue thickness of up to 0.8mm (0.033") for shear which is what we're mainly interested in and < 0.6mm for tension (0.024"). That's a thicker glue line that they were using in the Finewoodworking tests where the *loose fit* was 1/64" (0.016"). One other interesting point was on page 3, they say the failure of a 2.54mm joint (0.1") was 3.9kN!! and you're concerned about tiny gaps in a rod being filled and weakening the rod so it may break at 3.9kN????!!! I'm used to si units but is 3.9kN something like 28,000lb foot/sec? Whatever it is the bamboo has well and truly broken by the time it comes close to 1/10th of that. We're talking fishing rods, right? All those tests you've been quoting have done after glancing over it is convince me that my initial statement that it's impossible to make gaps in a rod that epoxy out of the bottle such as Epon 826 at 20c can't fill and still be sound. Can Epon even fill a gap of 2.5mm? You can test that can't you? I say it's impossible because when you bind the rod each spline is in contact with two other splines. No matter how manky the workmanship the splines are in contact, there may be tearouts, the planing may be out 0.010" or so if you're a bit careless, let's be generous and call it 0.020" but essentially there is physical contact. There is nowhere along the splines that a bound rod can have continuous gaps because the splines are in contact, if they're under or over sized that just nestle in and find their own way of fitting in with the rest. You can make a woodworking joint that the wood isn't in contact, it's a bad one but it's possible but you can't bind a rod where the splines aren't in contact other than deep tearouts. What is the largest gap you've ever seen on a rod? At worst it was a long tearout. How wide was it? How deep was it? Did the glue fill it? The tests you are quoting say a glue line of 0.8mm (0.033") is OK for optimizing allowable tolerances combined with acceptable strength but it also says a gap of 2.54mm will fail at ****3.9kN.***** So what??? This is a fishing rod. If the material you're gluing fails at a lower point than the glue, then the glue can't help no matter how strong the bond. If you have splines that are 0.020" off it's still inside of 0.8mm allowances. How bad does a spline have to be to have a gap of 2.54mm and still get used? I have to say it again, 0.033" is a wide glue line and that's the acceptable one in the report. That's twice the width of the 1/64th (0.016") gap in the Finewoodworking results. As a woodworker you'd hang your head in shame with a joint that bad, on a rod if you were that much out failing glue lines are the last problem you have. We're aiming for 0.001", most can prob get 0.005" or so without too much heartache but who aims for 0.030"? It doesn't even matter is there are internal gaps because the splines are not equilateral because as we all know the core of the rod contributes very little to the strength of the rod, most of the strength is at the boundary. Hollow rod makers know this. The makers of Epon have made 826 the thickness they have so that at the recommended 20c any gaps that it is capable of filling will not adversely affect the bond. If the bond was affected by the gap filling properties at that viscosity they'd make it thinner, so it could only fill smaller gaps. But they've determined using tests that at 20c the gaps it will fill won’t hurt the bond. There's no point in arguing that, they've thought this out, they supply it at that viscosity knowing it'll fill gaps of a certain width and they're happy with that. The reason I know this is because when you buy 44 gal drums of epoxy like the place I worked at the makers will ask you what temps you are using it in, and what you're wanting to do with it. They armed with this info make the glue to the viscosity you need so it's Goldilocks porridge for the job you're using it for. The boys at Epon have determined that the gaps it'll fill made as it comes from the bottle at 20c is OK for the bond. Argue that if you want but that's the way it is. Returning to the Finewoodworking results can't avoid the fact that the tests have shown not only comparison between different glues which show that epoxy isn't the strongest BTW but also absolute values at which the glues or the wood failed. The reason engineers love epoxy is that you need it to bond aluminium and carbon fibre and nonotubes and dis-similar laminations of unobtanium which nothing else will do but when it comes to wood and dried grass there are alternatives that are at least as good, and you have to say going on the test results better. In the tests the wood was failing as much as the glue line. If the wood failed that's as good as it needs to get. In the case of the loose fit of 1/64" (0.016") where the glue failed the glue was a what you'd have to call a fillet and it still failed at something like 2500lbs. Lets get that figure in our minds. I own a couple of lathes and milling machines. One lathe weights 750lbs, one 150lbs, one mill is 850lbs and the other about 125lbs. A combined weight of about 1800lbs so the glue line was still holding with all that machinery hanging from it with almost another 1000lbs to go. That's the glue line, not the wood. Not even a Dickerson salmon rod will hold that sort of weight. Bamboo prob isn't that much denser than the tropical hardwood they used as the worst case wood either so what applies for ike wood would very likely applies for bamboo, it's grass but it's closer to wood than Al. If you've never tried to glue teak you have no idea of how hard it is to glue. Makes bamboo seem like cardboard by compassion and ike is supposed to be worse than teak. My comment about using one glue regime and trying to apply it to everything was specific to epoxy. My point is that I suspected you were basing your opinions on Al or steel and I was basically saying that what you may be thinking of when it comes to keeping laminates together during a 9G turn going at Mach 2.5 is as different to making rods as boat building and you have to keep in mind that we're taking FISHING RODS that are made from dried grass with smaller gaps that matter when filled by EPOXY glue made to fill them. I just have to say one more time that a glue line of 0.8mm is a thick glueline, sorry to have to say it but I would consider 0.8mm to BE the gap. No, I'm not confusing matrix and laminates. You just have convinced yourself I have. I merely brought the subject up to say that the only time we used non-filled epoxy was to fill weave and that BTW Epon 826 out of the bottle at 20c would fill weave. My bad for bringing it up. Won’t do it again. I will repeat though, one coating of epoxy in glass weave can be broken by hand, you can't do that with three, you can try that yourself, can't you? (Tony Young) But if you keep reading past page 15 and onto the top of page 17 it continues to conclude that glue thickness is OK up to 0.8mm (0.033") for shear which is what we're mainly interested in and < 0.6mm for tension (0.024"). It even states that in the abstract.0.8mm is a pretty thick sort of glue line you know. So is 0.5mm. The thicker the film, the weaker the joint. The study proves that. The link I recommend iif you read it was not a marking hype. It was done and tested in a way that you should approve of and published in Finewoodworking. It's just to Titebond's advantage so they have it on their site. The testing was comparing joint strength of different adhesives. As I mentioned before, I could care less about the other adhesives, we were talking about epoxy. Did you read the article??? You're telling me that they did not properly test the pieces using good methodology with accurate testing equipment? Yes, I did read the entire article. It was all about comparative testing between a number of different adhesives. Not germain to the epoxy discussion at hand. To repeat the conclusion on page 17 of the report you sent the link to, those tests you're talking about were conducted on 2017 Al and in the meaty bit on page 17 recommend glue thickness of up to 0.8mm (0.033") for shear which is what we're mainly interested in and < 0.6mm for tension (0.024"). That's a thicker glue line that they were using in the Finewoodworking tests where the *loose fit* was 1/64" (0.016"). . . . In the tests the wood was failing as much as the glue line. If the wood failed that's as good as it needs to get. In the case of the loose fit of 1/64" (0.016") where the glue failed the glue was a what you'd have to call a fillet and it still failed at something like 2500lbs. Lets get that figure in our minds. I own a couple of lathes and milling machines. One lathe weights 750lbs, one 150lbs, one mill is 850lbs and the other about 125lbs. A combined weight of about 1800lbs so the glue line was still holding with all that machinery hanging from it with almost another 1000lbs to go. That's the glue line, not the wood. Not even a Dickerson salmon rod will hold that sort of weight. A complete non-sequitor. Think what a cane rod does - flexing back and forth with shear, tension and compression. The adhesive at the absolute center of the rod feels none of this. However, each section is made up of six pieces. There is quite a bit of adhesive, percentage wise of the total amount of adhesive that is not in the center of the rod section. That adhesive will see the forces of shear, tension and compression over the life of the rod. We're talking about a laminated cantilever beam hear, not a boat, and certainly not a constant force like the weight of a mill or a lathe. Bamboo prob isn't that much denser than the tropical hardwood they used as the worst-case wood either so what applies for ike wood would very likely applies for bamboo, it's grass but it's closer to wood than Al. If you've never tried to glue teak you have no idea of how hard it is to glue. Makes bamboo seem like cardboard by compassion and ike is supposed to be worse than teak. The issues with gluing up teak have to do with the oils in the wood. Not a factor at all in this discussion. Why did you bring that up? It's more porous than cane will ever be. My comment about using one glue regime and trying to apply it to everything was specific to epoxy. My point is that I suspected you were basing your opinions on Al or steel and I was basically saying that what you may be thinking of when it comes to keeping laminates together during a 9G turn going at Mach 2.5 is as different to making rods as boat building and you must keep in mind that we're taking FISHING RODS that are made from dried grass with smaller gaps that matter when filled by EPOXY glue made to fill them. Who the heck said anything about a 9G turn going Mach 2.5? What in the hell does this have to do with the discussion at hand? Why do you keep introducing stuff that has nothing to do with the discussion at hand? I just have to say one more time that a glue line of 0.8mm is a thick glueline, sorry to have to say it but I would consider 0.8mm to BE the gap. No, I'm not confusing matrix and laminates. You just have convinced yourself I have. I merely brought the subject up to say that the only time we used non-filled epoxy was to fill weave and that BTW Epon 826 out of the bottle at 20c would fill weave. My bad for bringing it up. Won’t do it again. I will repeat though, one coating of epoxy in glass weave can be broken by hand, you can't do that with three, you can try that yourself, can't you? Sigh. All right. I'll fall for this discussion of a composite matrix one more time. What is the application of that glass weave with the epoxy binder? Was it to be a stand-alone piece? Was it bonded to the deck or other portion of the boat? If so, you are failing to consider the other substrate the glass and epoxy are being applied to. Would you make a layup of a single layer of glass and three coats of epoxy if you were making a panel for something like a car or a boat? Multiple layers, with the weave going in different directions will give you the strongest panel. The three extra coats in your case are to fill the weave and give you a wear coating and a smoother surface for the finish, if the glass is epoxied to a deck or bottom of a boat. That's what gel coat does for you too. Smooth wear resistance on top of the fiberglass/CF/Kevlar weave. Adds a lot of weight too, but not a whole lot of extra strength to the matrix. But that is neither here nor there in the discussion of film thickness strength of an epoxy bonded laminate. (Mark Wendt) Depends on what you're laminating, and it also depends on if you're reading the literature from the Gougeon Bros who specifically do say West System at least is gap filling while maintaining strength within limits and they're talking GAPS not the tiny dinky little gaps you can make on a rod. They absolutely love to tell you it's gap filling glue while maintaining strength provided you use microfibers in the right ratio to glue.That's not to be confused with epoxy thickened to fair or fillet when you use microballoons which does tend to break away from the section it's filleting in time. Different epoxy makers specializing in different industries will have different ideas of course. Used to be that you had to make a good freshly planed surface and have well fitting joints or laminations and use very good clamping pressure etc but now, it's not exactly foolproof but it's a hell of a lot easier which is why epoxy is popular. If you paid a visit to a boat yard and saw the thickness of the epoxy they use when cold molding, you'd freak. When I worked at the boatyard we had the contract to build the Brisbane City Council cat ferries and maintain the existing ones on top of the other work we were doing. There were about 60 of us working there and we literally used epoxy by the 44-gal drum and went though more than one drum a week. On the ferries the glue we used for laminating hoop pine laminates that were 1/8" thick and 48" x 6" was something made in NZ I don't remember the name of because it was some uninspired name like autocrane industries and came ready thickened so there was no messing about with it and we knew there were no variations in the use. It was used in a 1:1 ratio, the glue was white, the hardener was pinkish, so you only had to be able to count to one and then do it again and be able to tell the dif in colour to be able to use it. I could even do the job hung over and often did on Saturdays it was so simple. The spreaders we used were plastic about 3mm thick and were flexible but firm if you know what I mean and were about 6" square. The epoxy AS IT CAME FROM THE MAKER FOR THE JOB was stiff enough in Brisbane summer temps to hold the spreader in an upright position for at least 30 seconds, prob more. That's thick by anybody's measure. The reason it was thick was because it filled gaps, that's why we used it and not resorcinol which we used a lot in other places and always for massive timber laminations. The epoxy was plenty strong for the purpose in which it was intended. You'd lather this stuff on like icing a cake, lay on a laminate, staple the laminate in place using copper staples and scrape the squeeze out and use it on the next section to be glued. You'd do that for 6 laminations all diagonally crossing over the lamination beneath it. In boats, the last thing you want is voids in lamination, epoxy fills them great, it's the best there is for the job, can't think of anything better. Voids have zero strength and worse from a boat point of view is that voids collect water which always leads to rot. Boats aren't rods nor aircraft doing supersonic speeds. Aircraft doing supersonic speeds aren't rods nor boats. What applies for boats wont work on a JSF and if you tried to use JSF lamination ideas in a boat yard you'd be told to do as you're asked and lay it on thick or find another job because you want the epoxy thick to fill gaps beneath the laminates and between them when cold molding. If you we were laying glass cloth on a deck we used West System straight out of the containers, no thickening because you needed it to penetrate the weave and stick to the timber under it as anybody who has ever made a cedar strip canoe can tell you but that's a completely different set of circumstance to laminating. You need that first drench of epoxy to completely penetrate the weave because you don't get a second chance to fill any weave you missed and subsequent coatings of non-thickened epoxy are to keep filling the weave because guess what? it's a good gap filler. Rods have been made using everything from horse hide to milk glue to epoxy and it all seems to work OK provided it's used properly. If your strips are made well they won’t have gaps so what does it matter what glue you use. If you have gaps acceptable to your own personal level of acceptance and beginners often fall into this category epoxy and titebond and probably Weldwood will fill them and provided you use the glue right the rod will work. The gaps that the epoxy will fill won’t weaken the bond in any meaningful way. Perhaps on the wing leading edge of a Dreamliner or hull of a high-speed boat it matters but not a rod. Resorcinol won’t fill any gaps at all but again the rod will hang together. It's easy enough to prove one way or the other. Make a couple of non-tapered sections, one as you use the epoxy, another thickened and another with voids that are filled with epoxy and hang weights of the ends until they break or run out of weights before they break. Once you have the answer ask yourself how often you've broken a rod in use and if you did, was the force anything like what it takes to break the test sections? This is from the Epon seller's site, I *think* it was 826 that was recommended. EPON 826 is commonly used to fabricate high strength fiber reinforced pipes and composites. The low viscosity of the resin provides rapid wetout of a wide range of reinforcing fibers including glass, graphite, aramid and boron. High fiber content with low void content can be achieved with this resin. Structural composites such as this have a high ratio of strength to weight. This makes them suitable for applications ranging from sporting goods equipment to aerospace structural members. I think the bit about low viscosity and high fiber contend with low void content can be achieved means it's thick and fills gaps effectively? (Tony Young) The spreaders we used were plastic about 3mm thick and were flexible but firm if you know what I mean and were about 6" square. The epoxy AS IT CAME FROM THE MAKER FOR THE JOB was stiff enough in Brisbane summer temps to hold the spreader in an upright position for at least 30 seconds, prob more. That's thick by anybody's measure. The reason it was thick was because it filled gaps, that's why we used it and not resorcinol which we used a lot in other places and always for massive timber laminations. The epoxy was plenty strong for the purpose in which it was intended. You'd lather this stuff on like icing a cake, lay on a laminate, staple the laminate in place using copper staples and scrape the squeeze out and use it on the next section to be glued. You'd do that for 6 laminations all diagonally crossing over the lamination beneath it. The reason it was thick is because additives were put in either the resin or hardener. The additives filled the gaps, and from what you describe, the laminate didn't really require high tensile or sheer strength. West Systems has a number of different resins and hardeners, some with, most without additives like microballoons, aluminum dust, fiberglass or carbon fibers or whatever other additives they have available. They also make different hardeners to work in different temperature regimes. That's why they publish literature, so you can select the correct components to do what you need to do in the environment you are working in based on the materials you are using in the matrix. If you we were laying glass cloth on a deck we used West System straight out of the containers, no thickening because you needed it to penetrate the weave and stick to the timber under it as anybody who has ever made a cedar strip canoe can tell you but that's a completely different set of circumstance to laminating. You need that first drench of epoxy to completely penetrate the weave because you don't get a second chance to fill any weave you missed and subsequent coatings of non-thickened epoxy are to keep filling the weave because guess what? it's a good gap filler. It all depends on the material you are laminating in the matrix. Porous materials will generally require slightly thicker resins and hardener combos so as not to starve the joint when the laminates are clamped together. Adhering non-porous to non-porous would require a thin resin/hardener combo. All you are doing with the additional coats of epoxy after the weave is filled is providing a surface that can be smoothened to apply finish. It does *not* make the matrix stronger unless you are adding additional layers of fiber. Oh, and it adds more weight. Think gel coat, which is nothing more than epoxy with coloring agents. No inherent strength, just a nice finish. It's easy enough to prove one way or the other. Make a couple of non-tapered sections, one as you use the epoxy, another thickened and another with voids that are filled with epoxy and hang weights of the ends until they break or run out of weights before they break. Once you have the answer ask yourself how often you've broken a rod in use and if you did, was the force anything like what it takes to break the test sections? Don't have to do that. The manufacturers have already done the testing to destruction, and come up with the film thickness that gives the optimal oint. The thicker the film thickness over what they recommend, the weaker the joint. And if you go too thin on the film thickness, you starve the joint of adhesive. This is from the Epon seller's site, I *think* it was 826 that was recommended. EPON 826 is commonly used to fabricate high strength fiber reinforced pipes and composites. The low viscosity of the resin provides rapid wetout of a wide range of reinforcing fibers including glass, graphite, aramid and boron. High fiber content with low void content can be achieved with this resin. Structural composites such as this have a high ratio of strength to weight. This makes them suitable for applications ranging from sporting goods equipment to aerospace structural members. I think the bit about low viscosity and high fiber contend with low void content can be achieved means it's thick and fills gaps effectively? You misread that. High fiber content and low void content means there's a lot of fiberglass/carbon fiber/kevlar/whatever fiber in the matrix and few to no air pockets (voids). Means you can use low viscosity epoxy to wet out the fiber and inhibit the formation of voids and still use a lot of fiber in the matrix because the resin is thin enough to wet soak the fibers. Has nothing to do with meaning it's thick and fills gaps. But you're comparing apples and oranges. This is a composite layup matrix, not a lamination. The composite layup matrix depends on the distribution of the fibers and the binder being able to hold them all together. The strength in the matrix comes from the combination of the adhesive and the fibers. Laminating is a whole 'nother animal. A lamination's matrix is two surfaces bonded by the optimal thickness of the epoxy. That laminate gets its strength from the laminates acting like a beam in bending. The adhesive is used there to maintain the two laminates in the beam. Get the adhesive too thick, and the lamination will eventually come apart when the laminate is bent back and forth. (Mark Wendt)
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