da Rock

K2r

No, it's not too late.
And if I were going to use expoy, I'd thin it with atecone so I'd have time to brush it on before it hardens in the cup.

bobrev06x

hey, good question there...."is it too late?"......my cap has some flights on it too and i would like to try ans save the thing if it's not too late. it's such a good little flyer, i dont want to lose it to something like that. any help out there? thanks

MinnFlyer

My Feedback: (4)

The Funtana's firewall is fuel-proofed at the factory. But if you want to add some insurance, remove the engine, clean it GOOD with epoxy, scratch up the surface with some sandpaper and coat it with whatever method you choose.

CGRetired

My Feedback: (1)

Mike.. clean it good with epoxy?

Dick

MinnFlyer

My Feedback: (4)

Ooops, Just checking to see if you're paying attention

Clean it with ALCOHOL!!!

CGRetired

My Feedback: (1)

DaRock. That's why I use fiberglass epoxy resin. Two part, hardens like a rock, and has a very long cure time.. gives you plenty of time to do things before it hardens in the cup.

DS.

CGRetired

My Feedback: (1)

Hi Mike.. ha..you got it..

Dick.

bobrev06x

man....what a great bunch of guys. thanks for all the response. got a shipment from the tower today. new dubro wheels (3 ") ribbed rubber. nice and hard. no deflection at all. this warrior is a little hefty at 9.5 lbs. and those foam tires were collapsing under the pressure. waiting for the 13/5 prop now. she should come outa the hole nice with that on there. but...i gotta treat the firewall.....ok guys, have a fun day.

da Rock

And that's why I use epoxy finishing resin. I seldom thin it actually. But it can be thinned with acetone. And I do use 30min epoxy but that's almost always thinned if I'm going to fuelproof/strengthen with it. And both cure decently hard and have a very long pot life. I've never had either kick off in the cup before I was either through painting or had used it all.

And I have used polyester resin for the same purpose. It's actually a little easier to work with and I've never felt the need to thin it. It does however STINK something awful. Since it also sets up a bit more brittle than epoxy, I've quit bothering with it. But it does a great job.

BTW, I'm not used to hearing it called "fiberglass epoxy resin". Polyester resin is often called "fiberglass resin". But epoxy is always just called epoxy. Of course, they both can be used with fiberglass cloth to produce a fiberglas finish or item. Is it a CG thing to throw in that extra word? I'm sorta confused by what the meaning would be...... but then, old age and confusion often combine. grin

bobrev06x

just got the firewall coated on the first plane. that was pretty easy. and it looks so nice...all shiney and stuff. i sealed around the fuel tank stopper with silicone and now i just have to re-assemble. nice.....two more to go. this should help alot.

LT-40

My Feedback: (2)

For fuel proofing I just brush on some water based polyuerethane. It is comonly used to water/fuel proof floatplanes, so I figured that it would work for my firewall, and so far it has. It may not be as good as the epoxy though.

LT-40

da Rock

It's extremely good at strengthening and fuelproofing the inside of the fuselage. It's very light weight and a bunch easier to use. Goes on.... uh.... goes IN with no fuss or bother. Just need a brush that reaches. I always coat the inside of my ARFs from the inside of the firewall back to where the TE of the wing lines up. Never know when the tank might leak. And the fuselage often could stand a bit of strengthening. And the stuff penetrates into seams that usually could stand some kind of gluing.

Chocks_Away

Is that polyurethane glue or polyurethane varnish ? [sm=72_72.gif]

bkdavy

My Feedback: (1)

Water Based polyurethanes (such as Minwax polycrylic) are NOT fuelproof. They offer some fuel resistance, and will prevent the fuel from soaking into the wood quickly, but they will soften in contact with fuel, and then you're protection breaks down. For fuel proofing, epoxy is hard to beat.

Brad

Montague

all water based polyurathanes are not created equal. Some are fuel proof, but others aren't. I believe that Minwax is one of the ones that isn't. I've had good results with "Zar" brand high-gloss from Ace hardware. YMMV though. And I haven't used it on the firewall, I was using it to put ripstop nylon on foam wings for RC Combat use.