Fuel-proofing engine compartment?
 

Hi Everyone! The answers to my question may come too late for me, but I thought I would ask anyway to maybe benefit others.
In my building of a Sig Wonder, I'm about ready to cover the plane, but before I do that I'll need to paint the engine compartment to fuel-proof it. What kinds of paint can I use to do the job? I already have; black "Supercoat" - it's a high-gloss butylate dope. I also have a "premium enamel" in red - can I use an enamel paint? Then I also have Coverite's "Balsarite" - clear. Coverite says I can fuel-proof an engine compartment with several coats of thier product. That's the one I'll use for this airplane.
But, what other kinds of finish can I use, in an engine compartment to help protect the underlying balsa?
I other reason I'm asking this question is for a wider choice of colors. Sometimes I don't care what color the engine compartment is and then sometimes I do. With this airplane I have a job to do (protect the engine space) but I have no idea what colors of covering I'm going to use to cover the plane - yet. I figure the Balsarite (clear) will go with anything.


Thanks for your feedback!!

Mike Kennedy
Cincinnati, Ohio

RE: Fuel-proofing engine compartment?
 

Mike , I usually cover the plane first , then seal the firewall area with epoxy . overlaying the epoxy onto the edges of the covering seals the covering down as well as prevents fuel from getting under the covering . the firewall can then be masked off and painted with any dope or fuel proof paint you choose . If you you paint or seal the firewall prior to covering you may not get a good bond between the covering and the sealer/paint and the covering may pull loose

RE: Fuel-proofing engine compartment?
 

I first cover my models and then mask off the area to be painted. I then paint, and then seal the paint and edges of the covering with Z-Poxy. Darker colors work the best because the Z-Poxy doesn't cure completely clear. I just used regular cheapo paint from Wally-World.

Hope this helps.

RE: Fuel-proofing engine compartment?
 

I used polyurethane varnish on my last project and so far it looks fine. I put on a coat before covering, and then one after wards to seal the covering edges.

RE: Fuel-proofing engine compartment?
 

A foolproof method (but time consuming) is to paint the inside area with an epoxy paint such as KlassKote. Do the painting as you build and before your cover. You may have to do some of the painting even before you finish building, paint those areas that will become inaccessible with a brush before you enclose them. Also, provide a drain hole at the lowest point in the fuselage in the tank compartment to allow that inevitable accident (if you plane lives a long time) where the tank either breaks, leaks, a fuel line comes off and fills the area with fuel.

RE: Fuel-proofing engine compartment?
 

Now that's a good idea[sm=thumbup.gif] especially about the drain hole!






I'm glad I thought of that;):D:D

RE: Fuel-proofing engine compartment?
 

I fuel proof as I'm building using epoxy that I thin with alcohol. I get the complete compartment behind the fire wall and in the tank compartment, front of the fire wall and inside the cowl area. Then I may use Klass Kote epoxy if I have the colors needed on hand. I also use Lustrekote paint or Ultrakote paint if I need a color to pretty up inside the engine compartment. I do everything before covering but that's a choice thing.

RE: Fuel-proofing engine compartment?
 

When I paint the inside of a fuselage, I always use a light color, preferably white, as it makes visibility inside so much better in case you drop a screw, need to thread a fuel line through a hole etc.

RE: Fuel-proofing engine compartment?
 

For reference, I've used Balsarite on all the planes I've built. Before I cover the plane I put several coats in the engine and fuel tank compartment and any places inside where I think engine exhaust might end up. I also coat places where I want the covering to stick. It works great for fuel proofing and holding down the covering.

RE: Fuel-proofing engine compartment?
 

I colored a firewall with a sharpie and then 'painted' it with epoxy. I warmed the epoxy to thin it rather than using a chemical thinner.

RE: Fuel-proofing engine compartment?
 

Fuel proof first, paint then cover.

RE: Fuel-proofing engine compartment?
 

I guess i am old fashioned but i just paint the inside of the tank compartment and engine area prior to covering with SIG Dope and add a 3/16 drain hole. I use 2 or 3 coats with a wide brush and have never had a problem with fuel soaking. I even had a tank burst with no bad effects a long time ago. I had a bad experience with epoxy coming off when fuel got on it but i am sure it was something I did wrong... The Black SIG Dope ends up looking pretty good in the engine comaprtment but watch the fumes!!! whoa!

RE: Fuel-proofing engine compartment?
 

I use dope too once in a while. If I have it on hand. Right now all I have is some in silver. Fuel proof paint I have in many colors just sitting around doing nothing and I always have epoxy and alcohol in my shop. A brain twister, why does my clear dope tend to dry up after being opened but the colored dope doesn't?? I can keep colored dope on hand for years, after I open a jar of the clear and put it back in the drawer it dries up in about a year? Just something you brought to mind.

RE: Fuel-proofing engine compartment?
 

[quote]ORIGINAL: Gray Beard
Store opened jars/cans upside down and they'll stay fresh for decades. Any minor seepage from the lid/cap hardenes and seals off any further seepage.

For cans, take a small finish nail or sharpened bit of music wire and punch about 4 holes in the bottom of the sealing lip where the lid mates into the groove. This allows drippage to run back into the can, keeps drippage from splattering out when you hammer the lid back on, and allows the lid to be hammered in tighter because the sealing groove isn't as full of crap as it otherwise would be.

RE: Fuel-proofing engine compartment?
 

Use epoxy thinned out with denatured alcohol and throw whatever color you want the engine compartment to be in the mix.