Bamboo Tips - Tips Area - Delamination

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I've been reading the archives and have heard some stories about delamination.  So I was wondering if there is a method that anyone uses that might make a better bond of resins and glues to the bamboo when gluing up?  I thought a good cleaning of the bamboo after planing to open the pores of the bamboo with a non residue cleaner like possibly brake fluid?   Cleaning the pores out (if there is such a thing).  Just seems like would make a better bond.  Anyone with any comments, experience, expertise??  (John Silveira)

I figure after all the planing on those strips that there is a clean enough place there for my glue and if it delaminates, I either screwed up, mixed the glue wrong, got a bad batch of glue, or some other assorted disaster. *G*

I have also gone to planing off a bit of the apex of the strip (thanks, Harry!) to help with that also.  (Dewey Hildebrand)

I always, always wipe my strips down with denatured alcohol on an old, worn-out golf glove before gluing.  It's amazing the crud I get off.  (Harry Boyd)

I always mist the strips (using URAC) just prior to applying the glue so the joints aren't starved for moisture.  Thanks to John Zimny (the Glue Guru) for that one.  (Brian Creek)

With all this talk about glues I got to thinking! (Probably a bad mistake!) Has anyone heard of rods becoming delaminated lately? I know all I have seen do this are real old ones. Topic for conversation?  (Joe Arguello)

Maybe we'll reach that age when we'll begin to see some of our rods 'delaminate' ~ if we haven't already!

All in fun(?)  (Vince Brannick)

I had a rod delaminate about 10 years ago. I glued the rod up with URAC 185 that was about 18 months old. Since then I've switched to Epon and have never looked back. Thanks to Bill Fink for the discovery of Epon for rodmakers. What's really good about Epon is that you have all kinds of time to straighten after gluing. With URAC 185 the blank was setting up just about when I got it out of the binder. For me, going back to URAC 185 would be a step backwards.  (Jim Bureau)

I know I had a rod glued with resorcinol from Golden Witch delaminate.  I talked to Ron Barch and found out he had had several delamination problems too.  Since then, Golden Witch no longer carries Resorcinol, I don't know why.  Ron speculated that they were cutting it with something but that was just a guess.  Resorcinol doesn't show much on a flamed rod if the planing is good.   (Neil Savage)

I had 2 rods delamination after using URAC. But it was my fault. I'd dried the rods completely in the drying rack and then glued them. The moisture was suck out of the glue by the cane. After that I experience, I then misted the cane prior to using URAC. Problem solved.   (Don Anderson)

Well, I was hoping to get a little more feedback on this topic, but the couple I got mimic my experience. I used URAC for many years then one day out of the blue I had a butt section come apart right out of the oven! I always glue one section at a time then I would heat set the blank immediately. Did this the same way for year! Anyway that scared me!

I started using Titebond III and have never had a problem, it is easy to use, non toxic, no heat set required, heat to straighten after dry not a problem and readily available. Not to speak of how easy it is to use, no variables such as mixing regiment. Beside that I know of a few well known makers that have been using Titebond (I, II or III) exclusively for their entire careers which is longer than I have been building, and I have never heard of a delamination. I guess that is what I was wondering, I certainly didn't want anyone named, but I am curious what problems are being had other than glue lines. Bottom line I think that most of the adhesives available today are far superior than the ones used when rods were delaminated. So as a good friend of mine always says: "just how hard do you want to make this?"  (Joe Arguello)

I always thought that the rods glued with URAC were stiffer out of the oven, I have a rod I built in 1999 (Ser. #9901) glued with URAC that I have been using almost exclusively since I made it. So now that I use Titebond III and compare the same rods, they feel the same, so is this due to that older rod becoming acclimated to the environment (absorbing moisture) or is it that I am trying to justify using Titebond. I really don’t think so and anyone who casts these new rods really like them.  (Joe Arguello)

I used the type of URAC bought from GW on my first four rods. I understood this was a product made by Borden, only it was called CR-195 or some such number. The same walnut shell flour, etc. so I assume it was the same stuff.

Anyway, this was about 6 maybe 7 years ago. I didn’t have any problems with that stuff. Then the CR number changed about 4 years ago, and I called the manufacturer to inquire why, and they said they changed the formula to make it less toxic. I think they said they removed the formaldehydes or something like that. Well, that’s when I started having problems. Two delaminations using the new formula, fortunately before the rods were even built. Both came apart while sanding the glue off. I talked to Russ at GW and others, and they also said to mist the strips first before gluing, and that would solve the problem.

By this time I had enough with the short working time, short shelf life, and sifting the walnut shell flower, anyway – so I switched to epoxy and also never looked back.

I noticed in the next Golden Witch catalog soon after that they quit selling the stuff (this was when they were still sending catalogs by mail). I don’t know if this was any correlation to the formula change or not, I never asked.  (Tom Vagell)

I'm still working on rod #1, and own very few rods by contemporary makers. But, with all the Grangers, Heddons, Phillipsons and the like I've owned and fished over the past 20 years I have only one rod delaminate on me.  This was a Heddon #35 I  found a  week after  Katrina, still  in  it's water-filled tube. Amazingly, I found  several sections of other rods still intact! These are 60-year-old rods! I know  Phillipson used resorcinol, but what did he use at the Granger factory?  And what glues did Heddon use?

As an aside, the step-down ferrules on these classic rods have never failed me either.  The exception to the 'never' is a Heddon that broke at the mid ferrule.  This was caused by water getting past the ferrule seal and rotting the cane, however.  (Reed Guice)

I think that a lot of what we are saying here is just due to ambiguous terms;  "glue line" referring to a fine, controlled line down the rod, due to the purple color of the glue, is not a problem to anybody.  Every bamboo rod has a number of glue lines equal to the number of strips!  On the other hand, a "glue line" that is a fault or series of faults caused by poor, inaccurate planing, foreign material or bamboo edge slivers not cleaned off the strips prior to gluing, chipping nodes or bad glue and/or poor gluing technique reflects an unacceptable level of attention to detail.

These rods may be sound and serviceable, certainly, but surely,  few rodmakers would allow them to pass out of their personal stable into the hands of customers.   (Peter McKean)

I have used URAC only once I had made a couple of rods as close as  possible to the same specs. After finally wrapping, took them out for a lawn test and delaminated both in lass than 5 minutes.  Swore I'd never use it again and I have not.  I know that Numbley thinks it is the cats meow, but my opinion is that it is the cats @%^&. (Ralph Moon)

I was using an all liquid UF glue for a while because I could get it from a place that was making kitchen cabinets and I could skim a little off the top of the drum as the cabinet makers got them. They always got new glue every month and just got rid of what was left over. I had some at one time that was about 3 months old and used it and had real problems. When I asked the manufacturer about it I was told that they make lots of different formulations. In the cabinet trade there was concern about the amount of formaldehyde in the work environment so the formula they used in the cabinet shop was reasonably low and therefore had a very short shelf life. The more formaldehyde the longer it'll last. They didn't think it was a very good idea to keep UF longer than 6 months once it was opened and a year seemed a long shelf life to the chemists but that may be fore what they were making and in now way relates to URAC or whatever you use. In any case it's wise to test to destruction your glue before using it and it's so simple to do it's your own fault if you don't do it and have problems.

All it takes is two lengths of wood of about the same dimensions and 6" in length. Glue about an inch of the ends together and let the glue cure. When it's done put one end of the wood in a vice and belt the other end with a hammer. If the glue fails deep six the glue, if the wood fails the glue is OK till next test. In the end UF just became too much trouble and I went to pin strip rods.  (Tony Young)

This is interesting, it seems to me that these delam problems happen immediately and would be more an issue of the glue actually not bonding rather than failing after a period of time! Whadda you guys think?  (Joe Arguello)

From what I saw the glue seems crystalline and cracks along the splines.  (Tony Young)

Last week ran a number of destructive glue tests involving Epon, T-88, URAC - walnut, and URAC with two ratios of NH4CL solution.

Upshot was that the usual 100 - 10 - 1 URAC - water - NH4Cl gave unpredictable results where the joint was sometimes quite weak while others were at least of "average" strength.  note:  I tried dampening the strips, but did not help - perhaps I don't know best method of dampening strips!

If the mix is changed to 100 - 20 - 2 of the same stuff, the bond is the best of all glues tested!  Tests of this mix have been repeated on 20 scarf joints and a couple scarfed and planed strips with same results.  All tests were done on scarf joints ONLY as I have an interest in nodeless...

Note:  "destructive" means the scarf glue test joints were bent and twisted by hand until something broke.

this may be of interest particularly is you want to try your own tests and see if the above "holds water" etc.  And, of course the usual disclaimers as to methods and results.  (Ted Godfrey)

Custom Pack (I think they now go by the name of C P Adhesives) used to sell a special wetting solution for use with their powdered URAC-equivalent adhesive.  Its called "Perkins GF-10" and the active ingredient is furfuryl alcohol, whatever that is.    I've still got a jug on the shelf in the basement. I'd offer the jug to anyone who wants it, but its probably not legal to  ship through the mail anymore.

CP has a page on how to mix & use powdered urea glue.  (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive)

I have had two tips delaminating over the years. One was a stupid mistake using polyurethane glue I rinsed the brush in methylated spirits and the tip came apart on my first fish.

The second time, I used Titebond III  and one of the tips came apart as I cut it to length. Could not find anything wrong with the two other sections (it was a three piece) and I have fished it for a couple of seasons without problem, Maybe I used too much water cleaning off the glue? Anyway I am back to using polyurethane.  (Tor Skarpodde)

As a newbie to this craft (I've been at it for about 1 year and have completed 8 rods - 7 glued with Titebond III) you can take or leave what I'm about to say.  With my first few rods I was noticing that the tip would take a set and I sometimes had them split when I cut to length.  I posted this dilemma on the list and the best answer I got was from a builder who did some experimenting with the cure rate of Titebond III.  He squeezed a blob of Titebond III on a piece of glass and let it sit to see how long it took for the entire mass to cure.  As we both know the exposed surface dried very fast, but it took almost a week for the center against the glass to fully cure.  His point was that the internal surfaces of our blanks must be allowed days/week to fully cure before we start putting too much stress on them.  I took his suggestion and have had much better success.  (Tom Key)

I usually let my rods cure for 4 days when using polyurethane and I guess I did the same with Titebond. So as you say that might not have been enough.  (Tor Skarpodde)

I was wondering if anyone has a good method for delaminating rod sections that have been glued up with URAC 185. In the last month I have glued up five rods (ten sections) using URAC and all but one are showing delamination to some extent. I was thinking about trying to disassemble the strips and start over using Epon. I tried to just split the strips out, but they are not coming off clean. I will have to redo two tip that I have experimented with but was hoping to avoid starting over on all ten sections. Suggestions would be appreciated.  (Will McMurrey)

I can't speak to strips which have been cured after gluing, but on an occasion having discovered a 'reversed' strip, (and a couple of hours drying), it was possible to insert a razor blade at the larger end and over a tea kettle spout, with steam VERY judiciously separate the strips. Then VERY carefully using a razor blade scraper, (also under running hot water) remove the glue residue remaining. Finished wiping down with alcohol, and drying thoroughly before regluing. Wipe in one direction only, from larger end toward tip. An arduous task at best!  (Vince Brannick)

That URAC is no good.   I have been preaching against it for years.  I don't think that you will be able to delaminate the rest of your rods.  When you want the damned stuff to stick it doesn't and when you don't want it to stick it does.  (Ralph Moon)

Many years ago, a friend of mine (very experienced rod builder) called me and related a experience like yours IE: glued up 2 rods and both delaminated while straightening. I went over to his place to see what could have happened.  Upon inspection of the strips under a 10 power eye loupe, there was very little if any walnut flour powder evident on the strips!! (Conclusion: Not enough powder)

I have used URAC 185 for over 25 years in bamboo rod construction, workbenches, and furniture, one of the very best wood adhesives I have ever used! THE Only adhesive I use, scarf joints too! I build only node-less rods!

Where did you purchase the glue and the date code? I purchase URAC only from the Nelson Paint Co. Iron Mountain, MI

How did you mix the glue. Did you follow the instructions? IE: by volume or weight? Remember, URAC is designed to fill gaps up to .020" using the directions on the can. I have read on this forum where people try to skimp on the ratio of resin to powder, IE: not using the recommended amount of powder trying to achieve invisible glue lines. The powder contains walnut flour AND the ammonium chloride. The URAC is activated by the ammonium chloride, the walnut flour is the gap filler.

Also note the instructions indicates 70 degrees minimum cure temperature!!

Here are my observations regarding URAC: it is very important to adhere to the instructions! AND, if you want to use URAC without the walnut flour for gap filling, then you need to use the ammonium chloride only! However, you need to have a very accurate scale to do this. Remember, we are NOT filling .020" gaps!

Here is my procedure (25 years):

As soon as I receive a batch of URAC, I mark the can with the date.

I mix up a test batch and spread it on a piece of wax paper. Into the hot box at 100 degrees F for 2 hours. IE: does it set up correctly?!? Should cure like a rock! Snap it into pieces!

Then I store the resin in the refrigerator. Should last for over 1 year!

My mixture is as follows:

40 grams resin

0.5 grams of ammonium chloride

This formula works for node-less scarf joints as well as binding a single rod section without glue lines!

Also, I preheat the resin prior to adding the ammonium chloride.  This might seem insane, but the glue is thinner!! Only mix enough to do what you are going to do without rushing the process!!

And yet another observation: URAC loves pressure! In other words, apply lots of pressure to the glue joint! This yields the strongest bonds!

Just a side note:

The process I use for building bamboo rods is very adhesive intensive, think EC Powell.

So I How do I know how to use URAC?!?!? I use lots of URAC in my process!!

As a side Note: I do not straighten any nodes or any single piece of bamboo. I split the culm and use machines in all of my processes and you can follow the bamboo grain lines on all of my rods from one end to the other!!

I hope this helps to clear the air on URAC 185!  (John Vorndran)

Does anyone have a way to delaminate a blank glued with URAC so that it can be scraped clean and re-glued?  (Greg Reeves)

I once tried delamming one with a heat gun once.  Once.  Ended up burning the blank before it let go.

I guess the only advice I can offer is what not to do! ;)  (Brian Morrow)

URAC is cross linked, so it will be difficult.  As a WAG, I'd soak it in acetone ( well ventilated and away from flames) and swell the glue.  This may also soften it enough that is will come apart easily.  (Dave Burley)

I don't know if it will work with URAC or not but every rod that I have delaminated on purpose was an older rod that was probably glued with hide glue or one of the early modern glues. I just tied a string to one end of the blank and put the sections into a PVC tube filled with hot but not boiling water. I then left them in the tube until they delammed, which usually took 1-3 days. It should go without saying but I'll say it anyway, not only should the wraps and guides be removed but the varnish should be stripped of first as well. If it is a recently made blank that hasn't been finished out you've saved yourself that much work.  (Will Price)

Put it in your heat treating oven at around 300° for half an hour.  Don't ask how I know that one.   (Larry Swearingen)

Here's what I found, I glued one up with URAC and got a strip out of order, read in Garrison's book about delaming a blank by soaking it. So I put the butt section in the bathtub with hot water and let it sit overnight. That @%*& blank is still as solid as ever! No luck on this end. Good luck wish I had better news and I hope someone else has a way of doing it.  (Joe Arguello)

If you haven't already done so, you might want to check with Nelson Paint Company who supplies URAC. 1-800-236-9278  (Doug Alexander)

Today I was lapping ferrules on an 8'6" Gillum Light Salmon. I did a test fitting - and the fit wasn't quite there - so I pulled the sections apart and noticed a rattling noise. I look at the tip and lo and behold the entire tip section - starting about two inches above the ferrule - and ending about an inch below the tip - completely delaminated.  There  are  no  cracks  -  and not  a joint  was spared (i.e. all six strips came clean apart).

Anyone have a clue why this would have happened? Here are some possibly relevant notes on my process

1. Glued up with URAC w/ walnut hardener as I have done on the last 10 rods.  Ratio was 100 grams urac 13 grams walnut powder.   The glue is stored in my garage and is less than 4 months old (at least from when Nelson sent it to me).

2. Hand bound - again - Ive done this on all of my rods.  The rod was bound and hanging within 20 minutes of mixing the glue up.

3. Let it dry for almost a week at room temp.

4. I did ammonia tone these strips for 24 hours (soaked - not fumed) - not sure if that could be related - but I've never heard of that.   I did this after rough planing - before heat treating and final planing.

5. After glue up I soaked it in Daly's Seafin Ship n' Shore for 20 minutes. It's been a week since I did this.

I didn't clean the strips very well before glue up - I brushed them off - but didn't use DNA, etc. to clean.  I haven't done that in the past but will in the future.

That’s all I can think of that would have had any impact on this.

I think I can just reuse the strips by putting them back in the forms and taking a very light pass on each side - then regluing. That being said - I'm real concerned about the butt section on this rod - and for that matter - every other rod I've made.  Also, if I attempt to reglue - I anticipating a problem reseating the ferrule and I have no room to  spare because the section is already cut to length.

Anyone have a clue what is going on - or can anyone help with a fix?  (Tim Aaron)

Sounds like you got some oil on that part of the rod before glue up.  Do you hold this portion of the rod during glue up? Just a guess.  (Dave Burley)

I suppose I could have had some oil contamination (not sure what from) - but I wear latex gloves during the entire glue up process.

The biggest mystery to me was why it delaminated on all strips for almost the entire length.  This makes me think that the glue failed.  If it were a contamination problem - I would have thought that the delamination would have been focused on that spot.  (Tim Aaron)

I'd think either you have some old glue or you made a mistake in mixing.  Did you glue both sections with the same batch?  i.e. did you mix enough to do both sections and then glue up?  I've also heard of rods being too dry at glue up and the glue didn't penetrate properly.  First step, IMHO would be to mix a batch of the glue and glue up some 3/4" pine.  Let the glue set up thoroughly and test to destruction.  If the wood breaks first the glue is ok, if the glue doesn't hold it's probably bad.  I heard Nelson ran out of glue late last year or early this year, so you may have gotten some that was sitting on the back of the shelf and shouldn't have been sent.  (Neil Savage)

I just thought it was in an area a few inches from the tip.  Guess I misread your question.  Hmmm.  So the glue was OK at both ends of the section, but not on the majority of the joint.  What is the likelihood you disturbed the joint after it had partially set?  (Dave Burley)

Maybe your strips were too dry?  I've heard folks say you need to spritz them with water prior to gluing up with URAC, to allow the glue to stick.   With failure over the whole length of the stops, this would be my bet.  (Chris Obuchowski)

Maybe your strips were too dry? 

That's my guess, too. I usually get the strips damp with a paint brush dipped in water, then snapped until the excess water is shaken out. You don't want standing water drops on the strips, just a darker color. Let them sit for 15 minutes, then glue. Complete failures with Urac are either caused by low moisture content, or trying to use it at less than 70°, assuming the stuff is not too old. If you heat treated the cane recently, it's probably the moisture that's the culprit.  (Tom Smithwick)

I tend to agree that it is a glue failure problem.

As for out of date glue.  Do you still have the mixing cup you used?  How did the remains cure up?

Do you sift the walnut powder? If so any chance you sifted out some of the hardener.

URAC needs some moisture in the bamboo to cure properly.  Any chance the strips got too dry?

Just a couple of thoughts from a newbie so you can take them for what they are probably worth.  (Rick Hodges)

I had poor joint integrity on a URAC glued rod last year that I ammonia soaked  prior to gluing. I am guessing that surface of  the strips were too alkaline, but I haven't replicated the process. The URAC glued several subsequent blanks with no problem. I have soaked glued strips without apparent failure, but I'm not sure I'm comfortable with that now.  (Larry Lohkamp)

Been there. A URAC delamination. Strips were too dry. Moisture in strips is required. I mist them before gluing. Problem gone. The failure was my own fault. I glued within 1 day or heat treating. The strips had no chance to suck moisture from the air. This is with a relatively humidity of about 50%. The failure occurred after about 50 rods had been built. Previously built rods had no failures but I'd waiting longer to glue them up.  (Don Anderson)

Knowing the appearance of the excess glue left "in the pot" might help us.  I had one problem with delamination due to insufficient ammonium chloride in the catalyst mixture. The leftover glue in the mixing pot remained light colored and rubbery rather than amber and hard as glass.  URAC will not harden without sufficient catalyst.  (Harry Boyd)

Thanks for the responses everyone.  I think the culprit was probably lack of moisture.  I have never had the problem in the past because I have never glued on the same day I heat treated.  Therefore, moisture had time to reenter the cane.  This time, however, I did.  I heated in the morning and by lunch had the sections glued up.  Plus, I added a few minutes to my heating regiment because the strips had been soaked in ammonia.

I think I will either start misting with water or shift to the ammonium chloride sans walnut powder.

Now I've got to figure out how to get this thing reglued.  (Tim Aaron)

I feel like a crying man in the wilderness.  For years I have decried the use of URAC because the only two rods I used it on delaminated after about two casts.  Bob (Nunley) swears by. I swear at it. 

WHY USE ANYTHING THAT CAUSES SO MANY FAILURES????

Sorry Bob and all URAC users. (Ralph Moon)

I have done between 40 and 50 rods and not had any failures with URAC following the mixtures by weight recommended by Nelson Paint - just my experience.  (Frank Paul)

I think the biggest culprit for those using the stock hardener is sifting.  If you don't sift, you get chunks of walnut shell in the glue, if you sift, you're likely to sift out much of the ammonium chloride that's mixed with the walnut shells.  I don't use the hardener provided, rather I use Ammonium Chloride mixed 10% by weight with distilled water then using that solution 10% to URAC and have had no problems since I've started using that mix (about 15 years).  I think that takes care of the need of moisture, too.  Most times I'll heat treat then glue up as soon as the sections are cool enough to handle, often several sections at a time and, again, no problems with glue failure.

I know many people use the stock hardener with no problem, but I'd strongly suggest, spending a few dollars on a quart of Reagent Grade Ammonium Chloride and using the water mix.  Nelson recommends against adding water to the URAC 185, but there are many rodmakers, including myself, Harry Boyd, AJ Thramer and many others that have been doing this for long time without any issues.

Larry's problem with ammonia toning then gluing has me scratching my head also.   Although I no longer ammonia tone, I've done it many times in the past, but I'd fume the rods in a tube, not soak them.  I ammonia toned after glue up and final sanding and have had no delamination problems with that process.  (Bob Nunley)

The 10% ammonium chloride solution that you add to URAC, is that 10% by weight or volume or could one use either measure?  If by weight, then I assume it would be 1 gram of ammonium chloride solution to 10 grams of URAC?  Am I understanding that correctly?  (Tom Mohr)

I've always understood that a 10% solution of X means that, in every 100 grams of the solution, 10 grams are X and 90 grams are diluent.  A solution that combines 100 grams of water and 10 grams of Ammonium Chloride is a one-eleventh (9.090909 etc. percent) solution of NHCl.  Or did I just flunk chemistry?

I also don't know, having just started to use URAC, if it would make a particle o' difference in the ultimate strength of the bond.  (Steve Yasgur)

It is actually a 9.09% solution, but I don't think it's that critical. Of course, I didn't think being a smarta$$ to my first three wives was that critical either,  and I was WRONG!  (Bob Nunley)

You are correct in %, but there is Molar and Molal, just to cornfuse things..  (Dave Burley)

Isn't it just a 10 : 1 ratio?  (Hal Manas)

Yes, I mix one gram of ammonium chloride to ten grams of distilled water, then I mix one gram of this solution to 10 grams of URAC. All of this is done by WEIGHT, not volume. I just use a small $40 digital scale I picked up at Staples to measure. Small but very accurate.

By the way, a quart jar of Ammonium Chloride salt is just about two lifetimes supply for a rodmaker!  (Bob Nunley)

Interesting point, Bob - "I'll heat treat and then glue up as soon as the sections are cool enough to handle."

Do you, then, always do your final planing to finished dimensions before you heat treat?

Do you use some sort of formula that allows for shrinkage of the strips during heat treatment, and do you find the process predictable enough on an ongoing basis?  (Peter McKean)

Yes, I'm at final dimension when i heat treat.  I don't plane, though, I use a saw beveler to get to final dimension.

I cut each strip a little oversize (how much, depending on whether it's flamed or blonde,  but never more than .002 over) and they come out dead on with the HT regimen I use.  Yes, it's very predictable, very repeatable.  (Bob Nunley)

OK, after answering several emails about this, let me explain what my situation is.

My saw beveler goes from pressed and straightened rectangular strips to a finished ready to glue up tapered strips in one cut. No roughing out strips, so I cannot heat treat at "roughed out" dimensions.

I only have two choices:

1. Heat treat at final dimension.

2. Heat treat the entire strip then bevel it.

The problem with #2 is that the heat tempered strips are a bear to cut. They cut the blade life on the saw beveler by half, and the blades aren't cheap.

Before you try to heat treat at final dimension, let me warn you, YOU WILL BURN UP A TIP FROM TIME TO TIME! Very tight temperature control is an absolute must or the tips will get fried.

Also, as many of you know, I'm very close to putting my new miller into action. It WILL require roughed strips and I will change my process when I get it into production by roughing the strips, placing them in Harry's heat treating fixtures and heat treating in the roughed stage. As I said, you WILL burn up a tip from time to time doing your heat treating at final dimension and I absolutely do NOT recommend that anyone do this... for me, it's just a matter of economics. Cheaper for me to replace a set of tips that I occasionally burn up than it is for me to constantly replace those side cutting saw blades... The cost of the blades doesn't bite quite so hard when you're getting 6 or rods from each set, but it bites the checkbook pretty hard when you're getting only 3 rods per pair. (Bob Nunley)

When using ammonium chloride as a catalyst, a 100:1 ratio gives good results.  That is 50 grams of URAC to .5grams of ammonium chloride.  By weight.  At 70 degrees.

Nelson does not recommend adding water to the glue.  (Chris Raine)

Chris is absolutely right.  If you call and talk to the tech department at Nelson Paint Company, they will recommend that you do NOT add water to URAC 185.  Of course, there were many of us doing this years before we knew we weren't supposed to.  I've never been able to get anyone at Nelson to explain to me what adding water would do that's adverse to the glue's performance, so I continue to use the water/NH4Cl solution.  I haven't had any glue failures using it that way, but the manufacturer does NOT recommend doing it.  They told me to just add ammonium chloride straight to the glue at 100:1 ratio, just as Chris recommends.

Me??? Well, you know that "Old Dog, New Tricks" saying... I am the consummate Old Dog, so I'll keep on using it like I am.  No problems yet... knock on wood.  (Bob Nunley)

Weird that Nelson does not recommend adding water to the NH4Cl, which I don't, yet I have never had a problem misting strips heavily, with water and allowing them to stay damp before applying URAC.  (Doug Easton)

Well - this morning I tested the butt section and another blank that had been soaked in ammonia just like the other.  All sections (4 total) delaminated without much effort (i.e. light bending).  Another blank made at the same time - but fumed rather than soaked - appears to be fine (i.e. no delamination after stress testing)

Since ammonia soaking is the common factor with the failures, I'm assuming ammonia was the cause (though I'm sure I could be wrong).

I'm no scientist, but I did a little digging and came up with what may be an explanation -

1.  I glued up with URAC - using ammonium choride (NH4Cl) (with walnut powder) as a catalyst

2.  I soaked the strips in Ammonium Hydroxide (NH3) (Ammonia) prior to final planing and heat treating - but presumably - there was some residual ammonia left in the strips at glue up - more so than would be present if you fume.

3.  (Here is where I really start stretching my scientific knowledge so please feel free to correct me) After glue up the blanks were heated to cure.  Heating ammonium chloride causes it to sublimate (separate) into NH3 (ammonia) and Hydrogen Chloride ( I realize the sublimation temp of ammonium chloride is around 350 degrees - so there is clearly something wrong with this theory).  Presumably then, the ammonia created during sublimation has something to do with curing the glue?

4.  By introducing more ammonia into the equation (i.e. soaking strips) - I essentially increased the amount of hardener I was using.  In other words, I created a situation as if I had used more walnut powder (or Ammonium Chloride) than directed.

5.  The resulting bond then had reduced shear strength because of the use of too much hardener.

I'm sure I'm missing something here - but the basic theory is that somehow the ammonia reacted with the resin to create a brittle bond.  (Tim Aaron)

I actually think you have it backwards.  Ammonium chloride is an acid salt and that is what is needed as a catalyst.  Having excess ammonia (a weak base) around in the bamboo, likely will prevent or reduce the acidity of the catalyst ,  especially at the surface of the bamboo, and alter the cure at the bonding site - therefore delamination.  You might have good cure of the adhesive in the mixing container and still have delamination.

Ammonia is a volatile gas, so after soaking in ammonia. solution, allowing the parts to sit around or mild heating to volatilize the ammonia should solve the problem.

BTW sublimation is just passing directly from a solid to a gas, but chemically intact. A common example is mothballs.  (Dave Burley)

My suspicion is that it is the alkalinity of the surface that causes the problem.  Many years ago when I was much sprier, I managed a floor crew doing strip and wax jobs on commercial space. It is the ammonia in the wax stripper that does the work, and if the floor didn't get rinsed well enough, the new wax would bubble off the floor. Rinsing with a dilute acid solution neutralized the surface so that the wax would stick I believe it was citric acid powder that we used, but it was a long time ago. I think Dave is onto something about the ammoniated surface interfering with the chemical reactions in the URAC. My failed blank was soaked prior to glue up. It was soft and took sets easily, and eventually the strips just peeled apart. Two blanks that have been soaked after glue up are stiff and springy.

I'm thinking that the risks aren't worth the effort and results with ammonia toning, pre or post glue up. Jeff Fultz's Browntoner for darker shades may  be a  better solution.  (Larry Lohkamp)

I had a rod section delaminate today for no apparent reason!!!  I had put 18 strips into a soak tube, and because of pressing business, had forgotten them.  After about 6 months, I found them, and went ahead and straightened them.  The stench was not too bad, because I had put some bleach in the water.

After planing them out, I soaked them some more in ammonia. 

I put them into an oven and then tempered them.

I glued them up immediately afterwords.  I used URAC glue, and instead of using ammonium chloride as the catalyst, I chose to use the supplied mixture of nut hulls and salts.  I understand that the powder should be mixed with the entire quart, but I am unwilling to use 12 dollars worth of glue for each fly rod.  I have been using this particular quart of glue for the last 2 years, even though it is starting to look like cottage cheese.

It was cold in the garage, probably around 50 degrees, but I figured that I would have more working time, as the lower the ambient temperature, the longer the work time for the glue.  I have ignored all instructions given to me by Nelson glue, and figured that one more would not be too significant.

So, to recap:  I didn't follow Nelson's recommendations.  I didn't follow procedures of successful rodmakers.  I decided to soak strips, immerse them in an ammonia solution, squirt them with water, and do a bunch of other things that I thought should be tried out.  And the sections delaminated.  I blame the URAC.  (Chris Raine)

Ha Ha Ha!
Hee Hee Hee!
EPON is
The glue for me.

Good old Epon,
You can bank it;
Sticks like faeces
To a blanket!

Hee Hee Hee!
Ha Ha Ha!
All the rest
Are under par!

(Let' s see you beat that for a second childhood symptom) (Peter McKean)

The only delamination I've had was with URAC.  I followed directions to the letter: new glue, no soaking & two weeks drying time in a drying cabinet.  About three months after the rod was finished eight inches of the tip delaminated.  I glued it back together with Nyatex and ten years later it's still in use.   (Ron Larsen)

"So, to recap:  I didn't follow Nelson's recommendations.  I didn't follow procedures of successful rodmakers.  I decided to soak strips, immerse them in an ammonia solution, squirt them with water, and do a bunch of other things that I thought should be tried out.  And the sections delaminated.  I blame the URAC."

This is always the way it is. When I was building graphite rods folks always had horror stories about their Flex Coat not setting up or coming out gooey etc. About 99% of the time it was simply because they didn't follow the instructions or did it in a cold basement or they experimented with adding things to it to slow it down, thin it, or kick it. I always followed the instructions and never had a problem. I have a friend whose company makes model train electronic gadgets. One of her favorite sayings is "real men don't follow instructions". I guess it holds true no matter whether it is model trains or bamboo rods, somebody always figures that they know more about a product than the manufacturer but then complain when it doesn't come out right. After reading all the problems folks seem to have with glues, varnish, cane, threads, etc., I'm convinced operator error if usually to blame.  (Larry Puckett)

It's amazing how many problems get fixed that way.

Nelson sends out a sheet that specifies a moisture range for glue-up. Instead the strips get dessicated in the misguided belief that ambient humidity ruins the strips, or they get doused with water to negate the previous possibility. Why would anybody spend a few bucks on a moisture meter and glue the strips like they're supposed to?

I must admit that I do experiment on occasion, but I keep a detailed engineering log of what and how, and measure what I do, so I will know how I screwed up a process that would work just fine if I just left it alone. (Larry Lohkamp)

Ya know, if y'all used Epon, you'd find the adhesive to be a lot more forgiving of minor operator errors.  Cool/cold shop - no biggy, just takes a little longer to cure (if you get impatient, you can always heat cure it).  Mixture off a wee bit - no biggy again, it'll still cure, and 9,999,999 times out of 10,000,000 it won't delaminate.  Strips aren't moist - no biggy, Epon don't care.  And, on a 95 degree day with 95% humidity, you still have at least an hour and a half working time with the mixed epoxy.  (Mark Wendt)

Seems sensible to me.  Maybe you oughta switch to Gorilla Glue?  ;-)  (Mark Wendt)

I have received responses both on list and off list from those of you who have had problems with URAC.  I don't doubt that you have had delaminations with the glue.   I also have no doubt that the delaminations were caused by YOU, and not the glue.

URAC is a great glue, and is used for rod making, bow making and the manufacture of plywood. 

Nelson has perfected this glue and has printed guidelines for its use.  They will include this data with your order at no charge.

The fact is, that you have abused the correct method of application of the URAC to the point where the glue joint failed on you.  Because YOU did it wrong.

The list is long, but a starved glue joint, too low of an ambient temperature, under catalyzation of the glue, having too much water in the strips, diluting the glue with water, overheating the glue to cure it, striking the rod section with a bead head nymph or split shot are just a few.

The purpose of this posting is to assure the majority of rodmakers using URAC that it is still one of the preferred glues for bamboo rod making.

Nelson makes a great product.  It takes a rod maker to screw it up.  (Chris Raine)

With all of the piddley things you have to be concerned with in using URAC, it takes a rod builder to be dumb enough to use it.  I only used it once, but I had a fresh batch, measured carefully  and oh heck I can't remember all of the other things I had to do.  Should have used some old glue that you just swipe on.  Works for me!  (Ralph Moon)

It's only piddly because some rod makers chose to make it piddly.  Take 50 grams of URAC, .5 gram of ammonium chloride, and mix together. 

Certainly faster than mixing any other 2 part adhesive!   (Chris Raine)

I take it these are the directions straight from Nelson.  (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive)

I spoke with Nelson years ago, and they did not like to give out information other than there was ammonium chloride in the filler.  After pressing the nice young man, he stated that a 100:1 ratio of resin to ammonium chloride would yield the same good results.  (Chris Raine)

I recently received a new batch of URAC from Nelson Paint. I specifically talked with one of their representatives   about  the  use  of  only ammonium-chloride instead of the filler. Based on a 100 gram of resin to 13 gram of wood-am-cl filler she indicated that the wood-am-cl filler contained 10 % by weight of Am-Cl or 1.3 grams. That is very close to the 100:1 ration indicated by Chris. The person indicated that a ratio of 100 grams of resin to 1.3 grams of Am-Cl would be appropriate. So I hope this helps with those who have been discussing the URAC resin and Am-Cl mixture for gluing up bamboo rods.  (Frank Paul)