mniesen89

So I'm reading the directions from the cub kit I bought and have not yet received in advanced just to review what has to be done and what I need. So far, the only thing kind of unknown for me is this:

"❏ 1. Coat the firewall and all other bare wood around the firewall with fuelproof paint or 30-minute epoxy thinned with alcohol. Fuelproof other areas of bare wood in the fuselage that may be exposed to fuel or engine exhaust, such as the fuel tank area and the front and back of the wing saddle"

SunDevilPilot

In my days of flying glow airplanes, where the firewall gets a little "slimy" from fuel / oil, I had good success just using some covering to protect the firewall. Not really sure why the manufacturers always leave the firewall as bare wood. You can coat it with epoxy but a single piece of coverings works just as well.

Covering works well to protect the firewall on gas airplanes too. Here is a photo of my Aero-Works 29% Edge firewall. I have been flying this plane for 4 seasons with no issue. The carb spits a little onto the firewall but I just wipe it off.

SunDevilPilot

mniesen89

I haven't gotten that advanced yet in my building career but its an excellent solution for when I do....thanks.

hugger-4641

My Feedback: (6)

A piece of covering is a great idea. A more expensive but less complicated way is to just use a bottle of thick or medium CA and just "paint' the entire firewall area with it using a small paint brush . More than one coat is good idea if you use medium CA. Multiple coats of thin CA will also work, but it dries so quickly you're more likely to glue fingers together with it.

outdoorhunting

I always use fiberglass resin on firewalls. It's very easy to mix, goes on easy &flows as smooth as a baby's butt ! It also works great with fiberglass cloth to reinforce wing halves when building, sands easy too!

Gray Beard

My Feedback: (-1)

They are just telling you to mix up a batch of epoxy then using 91 percent alcohol {bought at any drug store} and you thin the mixed epoxy with the alcohol so it is runny then coat the inside and outside of the fire wall with it. Then you coat the fuel tank compartment. I fuel proof from the wing bay forward. The reason for it is the fuel tanks or lines can leak and a glow engine sprays out a bit of fuel mist when running and the oil will soak into the wood softening it and softening the glues holding the plane together. It isn't near as bad with a gas powered plane. Some fuel tanks are better then others too and if they aren't assembled correctly the bung can come loose flooding the tank compartment.
Most hobby shops sell fuel proof paint but it isn't really designed to stand up to straight fuel. More just the burnt exhaust. Some people like to just use straight finishing epoxy instead of thinning 30 minute epoxy. How you fuel proof is up to you but it's well worth doing. I think it is Top Flight paint that is fuel proof up to 15%? I thin 30 minute epoxy and use that.

mniesen89

Gotcha....thanks all, for the sake of having to buy extra material, I'll probably stick with the epoxy idea.

eddieC

My Feedback: (2)

Lol, the tile says 'fireproofing' and got my attention. 

vicman

My Feedback: (10)

I usually use 30 min epoxy or finish resin thinned with denatured alcohol. The plus side of 30 min is that I can usually get something else done on the plane later in the evening as it cures quicker. Otherwise either works great. I got much better thinning results from denatured alcohol than the drug store stuff. Get some of the cheap steel handle acid brushes to put it on.
It really isn't that big a deal to do.

"Fireproofing" got me to look also.

Mustangman40

My Feedback: (1)

Boy I was expecting some pics of a burnt up plane with the title...lol


I always use 30 minute epoxy thinned with denatured alcohol, just thin it enough to make it like paint.. I use cheap epoxy brushes to paint it with, works fine....

carrellh

If you go with epoxy it usually only takes a few drops of alcohol to thin it.
Epoxy brushes, same as flux brushes used by plumbers, cost a lot
http://www3.omnimodels.com/cgi-bin/w...I=GPMR8060&P=7 are 30 cents each
http://www3.omnimodels.com/cgi-bin/w...I=GPMR8062&P=7 are 15 cents each
I bought a bucket of cheap paint brushes at a Hobby Lobby store that work well for this stuff. They were on the children’s art aisle and cost was 4 dollars for 144 brushes. This was a couple of years ago so they may or may not still be available.



If you want color on the wood, Top Flite LustreKote seems to be pretty fuel proof.
Cub Yellow http://www3.omnimodels.com/cgi-bin/w...I=TOPR7518&P=0
Primer http://www3.omnimodels.com/cgi-bin/w...I=TOPR7527&P=0

wcmorrison

My Feedback: (2)

Mix up your epoxy in a 2 ounce cup and then add about the same amount of alcohol as used in the epoxy. That thins it out. The alcohol evaporates but allows the mix to spread very easily and makes a thin surface coat. BTW it is fuel proofing, not fire proofing. Works for me.

adamle

After putting the epoxy on the firewall and cowl (if it is wood) I cover the model. Then a run a little bit of ca around the edge where the covering meets the epoxy. This keeps any oil from seeping under the monocote/ultracoat.

I also paint the firewall before putting the epoxy on. It gives a more finished look than just clear coated wood.

ARUP

Cover your airplane THEN put epoxy on firewall. The epoxy seals edges of covering.

OldScaleGuy

My Feedback: (2)

A lot of good ideas here that will work.
Personally, I use 30 minute epoxy thinned ~50% with 91% alcohol applied with an epoxy brush.