Thinning Epoxy Glue

Hi guys; What do you guys use for thinning epoxy glue when using it to coat tank compartments and cowlings? Seems like I remember someone using alcohol. How would dope thinner work? Thanks all.

Alcohol works although it needs to be free from moisture if you are intending to add further coats as, it is the dissolved water in alcohol that causes the surface waxing that can happen to laminating epoxy. You can also use acetone and that can be a better option as it evaporates quickely and leaves that epoxy to harden in its own time.

Regards

Mike

I tried the epoxy thinned with acetone and ended up with a coating that never quite hardened. It remained tacky for,,,, well it still is after a month... SOOOO what did I do wrong???

Did you mix the epoxy first then add the acetone? I have used both denatured alcohol and acetone depending on what was handy at the time, both worked well...

>Did you mix the epoxy first then add the acetone? I have
>used both denatured alcohol and acetone depending on what
>was handy at the time, both worked well...

Yes, I mixed the two parts, then thinned to the consistancy wanted. With everyones successes, I can only assume that I had a contaminent present either in the epoxy or the thinner. Guess I should give it another try... This time I'll mix a small batch and try it on some scraps first... Thanks guys

>I tried the epoxy thinned with acetone and ended up with a
>coating that never quite hardened. It remained tacky for,,,,
>well it still is after a month... SOOOO what did I do
>wrong???
>
>"Straighten up and fly right"
>Rog

Tom Dixon told me that he found one epoxy brand (Bob Smith brand I believe) that worked great with alcohol as thinner but tended to never completely cure with acetone.

I use methanol, as I use whatever brand epoxy I can get my hands on. I guess I should go to West systems, but I don't know where to get it around here (Central VA)

you can try warming it up with a heat gun to spread it with a brush.I have used actone with good results with fiberglassing a fuselage. Alan

Alan

I went to the local paint facility (one that does the painting) and bought a gallon of epoxy thinner and it has lasted for over two tears so far.
Jim, if you come by, I will give you a pint or so.

Bigiron

Man, I must be really off base........
I use the cheapest lacquer thinner I can find (usually the primer grade from WalMart in the auto section-$7). All my epoxies and the Zap resin, too. That and a heat gun. So far I have not had a problem in ?? years...... maybe ignorance IS bliss!
Bill <><

HI

Why don't you just use a very thin finishing resin such as ZAP's Z Poxy for that, you do not need to thin it, so you don't have to go thru any of the trouble or worry about if it will cure or not.

Regards

Thanks for the offer Marvin. I Just remebered I still have some epoxy thinner left over from when I used to use it for thinning K&B Super Poxy. That should work fine I think. Thanks to all you guys for your input.

LAST EDITED ON Nov-29-04 AT 08:04 AM (CST)
 
Acetone works great for thinning epoxy. It will slow down the 5 minute epoxy to about 8 minutes mixed 50/50.

I would not use alcohol. I once tried 100% alcohol 1 gallon can from the paint store and the epoxy turned into something sorta like melted bubble gum. I stired it with a screw driver and all the epoxy wadded up on the tip of the screw driver. It was worthless.

LAST EDITED ON Nov-28-04 AT 09:30 PM (CST)
 
Gary, you might have used "Rubbing Alcohol". It's about 20% water, among other things. I've used alcohol ("shellac thinner" from the hardware/paint store), and either dope thinner or lacquer thinner. Of the latter two, whichever it was made the epoxy really brittle. No problems with the right alcohol. Steve

I have tried all alcohol(isopropyl and methanol), acetone, heat gun, and thin epoxy. All work well if done properly. I prefer acetone to alcohol as it seems to dilute the glue better and sets up quicker. Only concern is acetone will attack CA glue, if there is any question use the alcohol.

Most epoxy manufacturers recommend using only gentle heat to reduce viscosity. Adding thinner seems to affect the strength and cure properties of the resin. If heat is not practical, consider using a low viscosity resin like West Systems 105 or Pro Set 125.
Derek Moran

Bob smith recommends Denatured alcohal. Works great for me. Don't use Rubbing alcohal, it takes a week or more to dry.

Hey Randy; I have used Z-Poxy before and still have some left, but it is about 10 years old, and very dark in color. I was a little concerned about using it. It is very good stuff though, but a little hard to find in my neck of the woods. I tend to use what I have when I am in a hurry and don't want to take the time to mail order. Thanks for the tip though.

I bought epoxy thinner made by Crown at a Pittsburg Paint store. It works great. A gallon (lifetime supply) cost about $10.
Jim