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Finishing - Dip Tubes - Varnish, Heating

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I would like to warm my varnish in my dip tube prior to dipping.  I have a 2 "PVC tube I use for by dip tube.

Any suggestions?  (Taylor Hogan)

I use my heat gun without the flaring tool. Move it up and down the tube about an inch away while turning the tube a quarter turn every two passes. When the tube starts to feel consistently warm to my hand I put it in the cabinet and dip away. It takes about 18 passes with the heat gun. Not very scientific but I have had good results with dipping.  (Steve Trauthwein)

I bought one of the heating things  used to warm home brew tubs.  Not the kind you put in the brew, it goes around the outside of the tub. It is a soft plastic strip.  I wrap it around the dip tube, turn on the switch and make varnish warm.  Works bloody well.  Cheap too.  (Peter McKean)

I have tried every conceivable elec. strip heater arrangement.  None of them worked.  No way to run a thermostat.  I use 1 1/4" copper tube with 2" reducers at the top. Have six of those loaded with different varnishes.  I also build boats so I had plenty of epoxy available.  Tubes were cleaned with coarse steel wool then coated, on the inside with 1/2 cup of epoxy.  Found an unused elec. ceramic dish heater and built a 5 ft. long, 6" PVC tube mounted on a 2 X 8.  Drilled a hole in the cap so the tube just goes down the center.  Before   start dipping I run the heat and the fan that is mounted at the bottom of the tube, with a cutout in the pipe.  Have a HIVAC thermometer in the cap. I use 85 degrees.  It only takes 10 minutes. to stabilize the temp.  Run the heater for a few minutes. every half hour or so.  Surprising how it holds the heat.  Have checked the temp of the varnish in the dip tube and it is the same as the exterior of the dip tube.  This is the best arrangement that I have found.  (Jerry Young)

Try using electric heat trace  cable spiral wrapped around the tube.  It is available in a variety of lengths.  You will have to defeat the thermostat which is enclosed in a clear plastic pouch.  All you have to do is slit the pouch and solder a jumper wire across the contacts because the "ON" temp is 32 degrees.  (John Long)

An easy way to warm the varnish prior to dipping is to simply remove the dip tube from the ground and put it in a warm place several hours before you dip the rod. I take my dip tube out from my basement floor the night before I'm planning on dipping and stand it next to my  4 ft fluorescent light, which is inside of my dip tank. By removing the dip tube and warming it next to the light each time I dip, I feel it gives me more consistency then if I'd of left it in the ground where the temperature changes from season to season. Also, varnish shouldn't be  applied at temperature's below 50 degree's, according to PPG. The varnish at about 70 degree's room temperature seems to work ideal for me.  (Jim Bureau)

At most auto parts stores you can buy a dipstick that plugs into an  outlet for  keeping diesel  engines warm.  They are usually 24-36" long.  Wouldn't this serve the warming purpose? Take it's temp and dip away!! (Pete Van Schaack)

I need a better way to heat my dip tube. Was thinking of using heat tape but have been told they don't make it anymore, some safety thing. Don't know if that is true or not. Anyone know of a source?

How do you heat your dip tube?  (Don Schneider)

Go to google.com. Type in “heat tape” and hit return.  (Larry Puckett)

McMaster-Carr,  page 438,  heat cable (Timothy Troester)

I just set my hair dryer in my box for about 15 minutes.  Works fine.  (Dave Henney)

You can heater tapes at Home Depot or your local plumbing supply.  (Al Baldauski)

I used two cheap bulb holder and two 100 watt bulbs with a baseboard electric thermostat, keeps my cabinet at 90 to 100 depending on the setting, works for me.  (Chuck Irvine)

I like your idea. It may be the simplest way.  (Don Schneider)

I'm not sure if my idea is any good but here's what I do. I use a system that essentially acts as a warm water jacket. I have a 1 1/2" PVC pipe sunk in about 4" of concrete in a 12" deep bucket, this tube holds the varnish. Around this tube is a 4" PVC pipe, this is the water jacket. I put a length of 1/2" PVC through the bottom of the big tube and out through the bucket wall with a shutoff valve glued to it to act as a drain. I fill the bucket with 4 more inches of concrete and this covers and seals the drain tube. I leave the top of the large tube open. When I need to varnish, I heat up a pot of H2O and dump it into the outer, larger PVC pipe. Let it sit for about 20 minutes and the varnish in the smaller tube is nice and warm. When I'm done I just open the valve on the bottom and drain out the water. I originally tried the same idea using a heat gun rather than water but this created a hot spot and didn't heat the varnish as evenly or as quickly. Regardless of the  method used, having the varnish tube firmly secured in the bucket of concrete was a big help for setting up. I have used or seen a half dozen other methods of setting up varnish tubes that didn't work nearly as well.   (Bill Felter)

I'm pretty new to this, compared to a lot of you. I've read some of your books and printed a lot of the info you have on the 'net.  I have a question about heating varnish in dip tubes.

I've dipped a couple of rods retracting the rod with a bbq motor at about 4 IPM with McCloskeys gloss spar varnish heated to around 100 degrees and it came out OK with minimal runs.  I've also heated the varnish to around 135 degrees and retracted at about 2.5 IPM. They came out glossier and generally an acceptable finish with minor rubbing.

Now the question.  What temps do you rodmakers think is the best or what temps have you had the most success with?  Is 140 degrees too hot and will it cause problems with delaminating or anything? I glue-up with Titebond III and I have about 10 rods out there being used with no problems so far.  I soak the glued-up blanks with Nelsonite wood stabilizer under 80 psi of pressure for about 2 hours.  (Charlie Dybus)

My process is similar but I think the varnish slightly with turpentine and don’t heat it beyond varnishing in a warm room.  I withdraw at about 2.5”/minute.  (Bill Lamberson)

A nice, slow draw  will result in a thinner finish.

As far as varnish temperature, look at the manufacturer's directions, which are printed on the can.  For most of us "warm" is what we aim for, in my case around 80 degreesF.  Try not to dry the rod at too high a temp either.  "Warm" is good, "hot" is not.  (Paul Julius)

I warm the room to 80 degrees F a day before I varnish so that all components are @ 80 degrees including varnish. I get very good results with no runs. I think your temps are too high.  (Tony Spezio)

I've heated my varnish to 200F in my dipping tube.  (Ken Paterson)

I didn't comment on this the other day, but it at least needs considering.  What will the heated varnish do to the one part glues, like Titebond III?  Going form TB Original, TBII and TBIII the glues get more flexible at room temperature, while they also get more water resistant.

It probably makes not much difference if the rod is totally completed, but in cases where the fittings are applied on top of the varnish, the incompleted rod may take this opportunity to move if the varnish temperature allows the glue to soften.

Just one more thing to worry about, I don't know of any problem in this case. Does anyone?  (Dave Burley)

Heating varnish to those temps may change the chemical composition by volatilizing off constituents. I also shudder at the thought of spilling 120 or 140 degree varnish on myself.

Viscosity is a function of temperature and thinning.  So you can also thin your varnish more to get the same effect as increased temperature.  (John Rupp)

I heat the varnish to about 80 degrees in the tube. My shop is in the basement and we keep the house cold.  I have to huddle around the tube to stay warm.  (Gordon Koppin)

As with every subject to do with rodmakers, I suspect there may be slightly more opinions than there are builders out here.

I used to heat my varnish, using an electric heating band wrapped around the tube.  I tried a range of heat levels for several rods each, and I also fiddled around with various dilutions and various diluents for the dipping varnish.  I use International Goldspar, and have for a long time.

The ambient temperature in my workshop ranges between about 15 degrees Centigrade and a high of possibly 35 deg in the summer.  I have found, really, that I get perfectly good results (and I am pretty fussy) just dipping at ambient temperature.

I pull the rod out at about 3" per minute, and I dip before I wrap on the guides.

Neither do I heat the drying cabinet, and it is in a separate room where the temperature is possibly a bit lower. My impression is that a heated drying cabinet for the varnish just sets it up too fast and prevents the varnish from finding a level while drying.  I find that the varnish works best when I just let it do its thing at room temperature.  (Peter McKean)

Then you must be cutting it quite a bit Peter? I would prefer to not heat it too but I'm not all that sure about what is best to mix with it and how much. Thought I would try Penetrol next as that's widely used by painters who want a good finish with oils.  Anybody have any other recipes?  (Don Ginter)

Actually, I don't dilute much.  I use Penetrol, but without trying to be cute, the amount I use has ben arrived at by hit and miss, due to the fact that I am never really accurate about how much varnish is actually in my tube.  But I estimate at this point, I add Penetrol at about 5%.

The viscosity of the mixture varies quite a lot, getting thicker as it ages, and I tend to add some artists' turpentine  ad  lib to correct the texture of the mix.

Another thing that I do, since we are only now, like this week, able to get Bloxygen in this country, is I strain the varnish quite often through one of those paper and plastic paint filters; and it is surprising how much crap (sorry to use the highly technical term there) gets left in the filter.

A point that I feel is probably worth making as well is that my setup is pretty low tech, and far from being worried about airborne dust particles, I get more concerned over things like airborne moths .  Long ago I thought about whether or not I really wanted to get obsessive about an everything-proof dipping setup or not, and decided not.  I routinely polish (?) every section after a month's drying of the varnish with Perfect It 1, Perfect It 2 and Finesse It, applied with a series of wooden-backed, leather-faced pads, and find that the surface after that treatment is about as good as it gets, even when viewed critically through a 4 power loupe.

Also, these spar varnishes are so good these days that if I get invaded by a moth or other sort of bug which hits the blank and sticks, all I have to do is flick it out with a #11 blade and the varnish heals itself perfectly by the time it has hung over night.  So, and I guess it is just a matter of temperament, I would sooner spend a planned few minutes polishing each section as a routine operation than get obsessive about a secure varnishing module.

As I said, more opinions than rod builders!  (Peter McKean)

I seem to recall that some of you heat the varnish in your dip tubes.

Seems I recall some kind electric tape or something you wrap around the tube. Can some one help with what you guys use. (Lew Boyko)

I used a heating tape and controller made for heating rocks and surfaces for reptiles kept in enclosures.  I believe I bought it on line from New York Pet Supply.  It works very well and brings the varnish up to the 90-degree F temp I find best in about an hour. I do recommend placing some insulation around the tube over the heating tape to retain the heat and get it up to temp as quick as possible.  I think any pet supply that sells reptiles will have what you need. (Greg McGowan)

Good idea! Thanks! I have limited space to support a dip tube but I think I will finally make the effort. Some of the more notable rod makers here in Montana actually heat their varnish to 100°... (Don Smith)