Hello, On the bottle, the directions state "thin with alcohol" What type of alcohol? Thanks, Ed

Isopropyl or Denatured.

Andy Dear
Lamar Mfg.

The higher percentage of alcohol (the lower percentage of water) would be preferred if you have both. For example,

De-Natured Alcohol (D-NA) = 91% Ethanol, 5% Methanol + 4% WATER.
IsoPropyl Alcohol (IPA) = usually 70% IsoPropyl Alcohol + 30% WATER.

Do not use any of the colored (green) or scented rubbing alcohols for any purpose in rod-building. That colorant or scent (usually an oil) may / will interfere. -Cliff Hall, B.S. Chemistry.

Yes indeed, Cliff has it right. Do only use as solvent or dilutant the alchohol that specifically states low water percentage. Then only buy it if it comes in a container that has an excellent seal to keep it from absorbing moisture on the shelf. Alcohol is hydroscopic, meaning it will absorb humidity from the air. Just leave a shot of scotch open on the counter for a day or two and see how cloudy it gets. That's absorbed water.

Thank's as always!!!! Ed

That all being said, and can't disagree with a word, I've never had anything other than 70% IPA in my rod shop. It works great for diluting 811. You won't have any trouble with it.

Putter
Williston, ND

Ok,
I have a question for you folks with a chemistry background. In case you weren't aware Gudebrod 811 is a water based urethane chemsitry, Gudebrod themselves says it's ok to thin 811 with water. Most of the waterborne urethane chemistrys I have dealt with work just fine when thinned with water.....So why all the worry over water content in the alcohol?

Andy Dear
Lamar Mfg.

I just want to know who can leave a shot of scotch on the counter for a day or two!!!!!!!!!!!!!!!!!!!!!!!!!!!! Talk about will power!



Mike (Southgate, MI)
If I don't want to, I don't have to and nobody can make me (except my wife) cuz I'm RETIRED!!

Wish I had will power... no way that puppy would sit there long.

I think the more water in it, the longer it takes to dry, Andy??? My best guess, anyhow???

Putter
Williston, ND

No wonder I never liked scotch on the rocks!

Andy your'e about half right. In case you weren't aware, Gudebrod 811 is a water base Urethane/ACRYLIC chemistry. Its the acrylic that is the barrier preventing penetration by subsequent coats of whatever. Its really the acrylic part of this chemistry that does the goodies that rodbuilders are interested in. Flex coat, U-40, and most of the other color preservatives on the rod building market are water base ACRYLIC formulations. The urethane/acrylics can be a rather touchy problem for formulaters. Water base does not mean 100% water as the solvent. There are specific solvents in these formulations that are there to reduce the solids sufficiently so that water can now used to thin them to a useable viscosity. Further thinning them with water can sometimes be disastrous. The solids can kick out of solution for one thing. Gudebrod is a marketing organization, they do a marvelous job of marketing other peoples products -- they essentialy have no technical ability. I have received some weird answers from them over the years. I can't sanction thinning a urethane/acrylic with water unless ---use distilled water, warm the water to about 100 deg. F, and add it very very slowly, and add no more than a max of 10% by Vol. You are safer to thin it with Denatured Alcohol, but you are always better off to not thin it at all. You are very aware of my position on the idiotic thinning of epoxies, I have similar position on thinning CP --- You receive a product with about a 30% solids content, which is marginal for the intended job-- and now you cut that solids further by thinning on the misdirected belief that it gives you better penetration, as if better penetration is going to do anything for you.

Ralph

I hear you Ralph. Some of the Gudebrod 811 that I've used is SOOOO thick, though. It's really hard to work with if it isn't thinned just a tad. Doesn't take much, but it's so much easier for me to work with when I do that. Do you think that's wrong?

Putter
Williston, ND

Thanks, Ralph - "ROQ" - Your comments carry about 100 times more weight around RBO than mine, even if I am on track & on target. As a benchtop chemist doing solvent extractions, I know that a multi-solvent system (2 or more solvent components), especially when carrying dissolved organics (acrylics), can easily be thrown out of balance by the addition of (even a small amount of) water. Precipitation of those dissolved solids, before soaking into the threads, will just leave a sludge or grit on the thread, not a penetrating infiltrate inside the thread, keeping out the final thread finish, and thereby "preserving" the thread color. -Cliff Hall+++

I agree with Ralph and Cliff. I too am a Chemsit by training (Inorganic-Analytical) I cut the Gudebrod with denatured alcolol. You do not want to "knock" the acrylic component out of solution. I have never used the U-40 product but I do know that the American Tackle CP is a ureathane dispersion that is loaded with surfactants that help in penatrating the thread. The Guebrod CP as a tendancy to sit up on top of the thread.better than the others I have tried. When you add alcohol you decrease the surface tension of the Gudbrod CP and get better penetration. It is very easy to over do the alcohol addition thus you will need multiple coats to ge good color protection. I have found that you need to add alcohol in very small amounts untill you get some sort of reasonable viscosity to both coat and penetrate at the same time. (This not an easy task and it does not take much alcohol) I have never tried the Scotch approach but I might suggest moonshine as an alternative. They still make some clear stuff here in the mountains of Western NC.

Ed Smith

Randy
There is very poor quality control of the Gudebrod 811, and Gudebrod doesn't have the technical capability to know it, or to do anything about it if they did know it. They simply buy it , label it, and sell it. Practically every paint company in business these days makes some kind of urethane/acrylic the same as or very similar to the gudebrod 811. For our purpose -- which is maintaining the original color of nylon threads-- I still like to use the straight acrylics, even though the finished film does not have the structural integrity of the urethane/acrylics. Are we worried about structural integrity on our nylon threads? You should be able to buy a new bottle of 811, check the viscocity when you open the bottle and if its to thick ---- add about a teaspoon( per 4oz bottle) of DENATURED ALCOHOL, and stir thoroughly DO NOT SHAKE. That should last you for the life of the bottle. Don't use isopropyl, it has to much water content, and does not have the diluent properties of denatured.

Cliff
You have hit on the reason so many people out there skip from one color preserver to another trying to find one that will work. @#$%& bells they all work when used properly, but using properly does not mean shocking the gee whizzes out of the polymer by stuffing H2O down its throat in the naive assumption that thinning will give it greater penetration. Instead of adding a film of acrylic, all they have when the solvent dries is a worthless sludge which leaves the threads badly mottled when the epoxy is added. These guys that thin the first coat of cp, then follow that with two coats of unthinned are getting away with it because the subsequent two coats are covering up the sin of the first thinned coat. They are also supporting the myth that thinning gives better penetration. In order for these water based systems to work, the formulator is forced to add a considerable quantity of surfactants (soap) to get the dissolved organics into solution. This surfactant technology is a specialized field all of its own, and the ratio of surfactant to water solvent can be very critical. Water is a very neat polar solvent, but it usually needs some help when dealing with organics. When adding more water than the original formulator calculated, one is not only risking kicking the solids out of solution -- he has also diluted the surfactant/water ratio to where the thinned solution will not wet out -- call it penetration--nearly as good as the original. Yet the myth goes on, thin it and it will penetrate better -- such nonsense.

Ralph

Hhhmmm.... 30%? I think you're being generous. I have had 2 seperate chemists both with PhD's in chemical engineering and both from seperate companies run tests on the 811. Both say the solids content is aproximately 13-15%.

Andy Dear

Ralph,
You said "Its the acrylic that is the barrier preventing penetration by subsequent coats of whatever. Its really the acrylic part of this chemistry that does the goodies that rodbuilders are interested in.

That may be true as it relates to 811 or Flex Coat or Trondak, but there are lots of other compounds out there that will work just as effectively, with better long term performance and durability.

We are having tremendous success developing a CP with dispersions that contain no urethane or acrylic, and that wear like iron.



Andy Dear
Lamar Mfg.