How do i fuel proof the engine area of my Four Star 60? What do i use?

NMTR13

Use some Epoxy cut with a little alcohol.


Dbow

Rustolem Paint brushed from a can in the color of your choice. Just make sure the paint is dry before exposing to fuel.

2 hour epoxy brushed in. No alcohol... it can leave the epoxy porous... (like a sponge.) Porous epoxy might as well not be there at all.

20-minute "finish cure" epoxy also works (no alcohol).

I thin epoxy with denatured alcohol and paint the mixture on.

Epoxy thinned with alcohol works great. So what if it becomes porous? You are not using it for structural strength, just a covering.

Porous... like a sponge = full of holes. The epoxy lets the fuel seep through it. If the alcohol can evaporate out of the epoxy... then its full of holes and can let the fuel in.

Its kind of like trying to hold water in a piece of window screen... it just doesn't do a good job.

I used finishing epoxy for the engine and tank compartments. Two or three spray coatings of clear lusterkote will work too.

Well, darn it, I guess I'll have to remove the ten year old epoxy fuel proofing I have on several of my planes because it won't stand up over time.

Trust me nmtr13, it works just fine.

You can eliminate any "porosity" in alcohol-epoxy mixture by not using too much alcohol and leaving it to cure in a cooler place in the house to avoid rapid outgassing that may lead to the "porosity".

Even if there's any "porosity" it's normally "closed porosity" and not "open porosity". Fuel should not seep through that layer as per Minnflyer. Did I cause enough confusion ?

Won't dope fuel proof your plane also? I'm planning on using some on my plane..

Yes, works real good....so does thin CA-even though I'll catch a lot of flack for that one (did before) Rustoleum, epoxy ect. the choice is yours. Your dope would be color matched though.

Jetts

The only problem with CA for fuelproofing... Nitro can dissolve CA. The CA is fine for protection from the exhaust oil... but fresh fuel can remove it.

It takes a while... or CA hinges would be serious problem

Told you so! Told you so!!!! I knew I'd hear it!
Yes FH, it will soften it after awhile, a loooong while, but I've used this method on quite a few planes, and they always ended up uh...."retired" before the fuel proofing went away.

Jetts

Well.... I just couldn't let you be dissapointed

Yes, CA is OK to fulprrof small areas. (kinda expensive for large areas)

So I can just squirt thin ca all over the engine area or I can use epoxy thinned with alcohol. If i use the epoxy how do i know how much alcohol to use? What Rustoleum and where can i get it?

Also can someone PM me, for some reason im not recieving any PM's...

Nmtr, don't use ca in such a large amount. You might develop ca allergy and respiratory problems. Even when used in small amounts, do it in well ventilated areas.

Here's a thread on alcohol/epoxy ratio :

http://www.rcuniverse.com/forum/m_14...tm.htm#1408587

With finishing epoxy, you don't have to add anything

Did you manage to resolve your hinge gap problem ?

Yes its much better now, before i did it i got scared because i thought i would have to take off the vert. stab. to get the elevator off but i didnt have to.

Ok now I have some rubbing alcohol in the house, can i use this instead of denatured?

Why can't you use either 2-hour epoxy or 20-minute finish cure epoxy? Those are already thin and flow like water.

Yes, rubbing alcohol will work, just add a bit after you've mixed the epoxy 'til it's the consistancy you want (like paint).
Thin CA you can use drop by drop, but as posted above, don't get carried away, don't breath the fumes, and yes it will be marginaly more expensive.
Rustoleum is available at K/Wal-Mart, Lowe's, Home Depot, ect.
Clear (or pigmented) dope is real cheap, already the right consistancy, and fuel proof right out of the container.

Jetts

Ditto on the finishing epoxy

http://www2.towerhobbies.com/cgi-bin...?&I=LXBH71&P=7

watch out with denatured alcohol... that porosity thing I mentioned above... gets worse as the water content increases. Not all rubbing alcohol is equal.

Also... rubbing alcohol can turn the epoxy rubbery. If that happens... you CERTAINLY have no strength from the epoxy (not as big a deal for fuelproofing as other places...) and... the epoxy can just peel free of the wood with no warning. (Then it definitely isn't helping fuelproof anything.)

Messing with the chemistry of epoxy just isn't worth the headaches it can cause... Yes some people get great results. I have TRIED the alcohol... and followed the directions given by the experts on doing that EXACTLY... and ended up with a goo that never set up.

I use good old Balsarite. Next thing to butyrate dope.