Notes on fuelproofing
 

Here are some recent results for you guys. I just got done doing a fuel-proofing on an all wood engine test stand. The wood is new, sanded, clean, no dirt, oil, fuel residue etc. I used 2 packages of the Loctite 90 minute epoxy available at Ace hardware. The kind that comes in the double syringes. A small foam brush was used to apply it.

The temperature the day I did it was about 60F. I squeezed out the epoxy in both syringes completely onto some scrap plastic. It's tough squeezing the clear side out. It no doubt would have been easier had I warmed it a bit in some water beforehand.

So with both tubes empty and the epoxy sitting in a scrap plastic container, I added a bit of 70% isopropyl rubbing alcohol. Then I mixed everything. I know, apparently it's better to mix the epoxy first and then add the alcohol, but this is the way I did it.

Ok, so mixed it really well, and then tried to brush some on...no go...not thin enough. So added more alcohol and mixed until it was a milk like appearance and seemed thin enough to brush. That went fine. I brushed everything really well. Then I hung the various pieces on a coat hanger to dry. I brought them inside to finish drying since it is warmer.

After 24 hours they were still tacky and left some residue on my finger when touched. Hmm...so decided to see if heating the pieces in the oven would help. Now mind you, they were not wet anymore, just tacky. So I preheat the oven to 350. Then once it got preheated, turned it off and put the parts in on some foil and into the oven. I closed the oven and just let them bake while the it cooled down. After about an hour and a half, took them out.

The results seem to be good. The tackiness is for the most part gone now. The wood darkened a bit more. So it seems to have worked for removing the residual tackiness that was there after 24 hours of just curing in the air. It does smell a bit when doing this, so best to have a day where you can open the windows.

After having read some of the other posts here, I think if I were to do it again, I would just use some automotive spray clear coat. Apparently it is fuel proof from what others have said, and would be much easier and quicker to do.

Another note on the brush-ability of the epoxy. It is very tough to do with a foam brush with only a little thinning of the epoxy. Maybe an acid type brush would have worked better, but I had a large area to cover, so I needed it thinned quite a bit.

Hope the info helps some.

Notes on fuelproofing
 

You know you dont have to make things so hard for yourself...

just spray the areas you want to fuel proof with humbrol enamel paint, thats what i do and it works fine for me :D

Notes on fuelproofing
 

with the syringe type epoxies, it is possible to not get the correct ratio if you mix too small of an amount. (a sure sign is that it is still tacky in 24 hours)

Notes on fuelproofing
 

Yes, I understand there are most likely easier ways. I don't recall anyone posting that Humbrol paints were fuel proof though. I remember them in one hobby shop from 20 years back..sold in little metal cans. If anyone has more info on Humbrol please chime in.

As far as the epoxy mix goes, I completely emptied each tube as much as it would allow. But it is hard to tell since there were some air pockets on the resin side.

After the oven heating, it's useable now, so that's the main thing. It wasn't any major project. And it was a good way to test the method. It's just an engine test stand, so it was no big deal if it didn't work out.

I know there are other simpler ways to go about it. Next time I will give the clear automotive spray a try.

Re: Notes on fuelproofing
 

Ace also carries a product " water-based polyeurathane" just brush it on,( with a foam brush) dries in about 1/2 hour and is fuel proof!! My personal favorite!

Notes on fuelproofing
 

I also use a polyeurathane finish, the same stuff you put on furniture. No mixing, just brush it on. One can will last a lifetime.

Tom

Notes on fuelproofing
 

What finish type on the poly are you guys using? Satin or gloss? I have heard that gloss finishes are more impervious to various things.