When mixing epoxy to fuel-proof a firewall, should you add something to thin it out ?
I think I remember reading in a post that you can mix in a little bit of alcohol and get good results...
Is this true ?
The last time I put a coating of epoxy on a firewall, I used 15 min epoxy and did not thin it with anything.
It seems to be a little thicker than it needs to be.

You can thin the epoxy with a little bit of alcohol. Don't put any more in than is needed.

An even better solution is to use your heat gun. Use an epoxy brush to paint a little bit of epoxy on, then use your heat gun which will cause the epoxy to thin and flow into the grain. After your firewall is coated, let it dry normally.

Either way will coat your firewall

Hope this helps.

If you use alcohol to thin it, make sure that the 2 parts of the epoxy are completly mixed together first. Then add only a few drops of alcohol at a time and throughly mix it in until it is as thin as water. [8D]

needs to be DENATURED ALCOHOL

not that alcohol in you med cabniet

excellent advice guys...

thanks all.

I had to do this 30mins ago on a repair i was doing.Didnt think of alcohol to thin so just used the epoxy straight.Well now i know

actually 91% alcohol works great. You can get it at the pharmacy just like regular strength alcohol. Works perfectly.

Hard to find denatured alcohol up here. Did some research and found that the denatured alcohol is basically pure or almost pure non-diluted type. If you read the labels "campstove fuel" is the same thing and readily available. I bought a small 1 litre bottle and tried it. Works great! [8D]

IMHO using alcohol from the pharmacy is a big no-no. most of it has far to much water in it and, if you use it often enough as an epoxy thinner, sooner or later you will wind up with a tacky and uncurable mess. The best solution is to use that heat gun mentioned above. If you must use alcohol, be sure it is denatured.

I've used ethanol which is almost pure alcohol, but the supplier here in Japan, a paint outlet, only sells an ethanol/acetone mix, 75/25%.

Acetone is used to clean up the brushes etc., so you should be able to use straight acetone to thin epoxy if you need to.

Don't use acetone around foam as it melts the foam. I built a foam cored flying boat, and 25% acetone is OK, but I wouldn't go any higher.

Retired Aviator,
Down here we call it Methylated Spirit, Can get it anywhere.

Cheers.

ONE WORD "ACETONE"

Or denatured alcohol. They both work well, but should be use sparingly because the final product is not as strong as unthinned epoxy.

Why not use some fuel proof dope to coat the areas desired ? ? ? ?

Ditto to Vagent. You can buy some fuel proof dope...clear...for like $5.00 a bottle. It'll last several airplanes and works great.

I can usually find it at Home Depot.

I usually "thin" epoxy by warming the resin and hardener by placing the bottles in a pot of warm water for a few minutes.

DaveB