View Full Version : Firewall solution??

02-13-2011, 01:49 PM

I kind of screwed up in the beginning by not installing a firewall blanket prior to sliding the boot cowl on. However, had I done that, I didn't know how to deal with all the fasteners and pass throughs on the firewall and get to them throughout the build process.

Problem now, how do I insulate the firewall and make it look decent? I have some KoolMat insulating material, but pieceing it out, getting it to lay flat, and securing it is a pain. I have also cut and pieced together some foil insulation, but again, it looks like crap and securing it is less than optimal with it laying on all the fasteners. Also, getting it all the way to the top of the firewall is next to impossible, so, I,m not even getting full coverage anyway.

What are some of my options?? Also, have any of you run with no insulation in there? My exhaust is a Sutton and sits up front so minimal heat is on the firewall. How much noise is associated with no insulation on the firewall? Again, I can't get full coverage anyway with pieceing this together, so noise may still be a factor.

Any ideas, suggestions, comments, opinions are certainly welcome, as this is starting to drive me nuts.


Here is a couple photos: all the fasteners in the way, and my pieced together quagmier tha looks like crap.

02-13-2011, 02:13 PM
leave it off--a little louder but with the Sutton not so much heet. but then again you live in Iowa. Your insulation job looks fine, are you building a show plain or a have fun plain?


02-13-2011, 02:22 PM
No show plane here Dennis, but a a little eye soar still bugs me. I guess the noise is my big concern. I have no other insulation as far as behind the side panels or anything, so don't know how much the firewall insulation will matter anyway.

02-13-2011, 02:54 PM
Looks like you've done a fine job with the cut/fit/paste of your foil but like you said, looks like "foil" :) (if you care about that).
Only thing now is to cover it w/something else. Perhaps you could (first) install some fastening strips (of skinny plywood?) and then screw whatever material to that. I was told, and makes sense, that NOISE is the main enemy to defeat through the firewall. There's enough ambient noise in cubs anyway.
I cut my interior panels out'a skinny plywood (door skins) & contact cemented real light naugahide over that. Tough enough to take a minor beating, & is light & cleanable, and flexible enough to bend around obstacles. Paint/cover w/what'cha want.

02-13-2011, 08:06 PM
Nimpo, that is not a cub, but a CHUB!

Steve's Aircraft (Brian)
02-13-2011, 09:18 PM
A few years ago I did a custom cub build where the owner opted to not put a firewall blanket or front interior panels....I custom cut the front floorboard to fit against the boot cowl. The firewall was also made from Titanium and he used the Leading Edge exhaust system.
The owner of this cub has never complained about excessive noise or heat out of this airplane.




02-14-2011, 12:56 AM
Nimpo, that is not a cub, but a CHUB!

Well, I was always conscious of weight, but not real anal about it. My Cub does beat the neighbor's 0360 off the water by 1 second, tho.
(mine is a "massaged" 0320 by Uncle Bart)

How's the Ruptured Chicken coming?

02-14-2011, 10:21 AM
Thanks for the pics of that one Brian. That's interesting.

Thanks also Logan for the response.

02-14-2011, 11:52 AM
Can you still pop-out the foil sections? You could get some nice fabric or Naugahyde from fabric store and spray glue to the foil pieces, then re-insert. Would probably look pretty nice. Just a thought.

02-14-2011, 12:32 PM
How about going with some fabric of some sort, with slits/holes cut in it to let the cables and stuff come through, then secure it with some stick on velcro? That way you could get it out for inspections/maintenance and it wouldn't be too much of a pain to remove or install. Maybe some headliner material, as it's easy to expand around tubes, etc.???

02-14-2011, 01:01 PM
I have read that some of that foil stuff will burn easily. Not sure if it matters to you, but something to check.


02-14-2011, 01:27 PM
Bugs, I have been looking into that idea. Some of my interior upholstry fabric stitched onto the face of those foil pieces and reinserted. We'll see how that works out.
HTJ, that gives me some ideas as well, maybe some velcro incorporated into the insulated panel idea.
Tim, this is actual firewall insulation that is rated to such and such. My interior upholstry fabric is also rated to fire standards. Not to say it wouldn't still cause a problem, depending on the situation, but trying to stay with all the fire rated stuff.

One of the issues I'm still contemplating is, that I can't reach the upper third of the firewall anyway due crap in the way. So, I may try it with nothing initally, and then start with the insulating and see how much noise I can cut down on just doing the parts I can reach. All good stuff here. Thanks for all the ideas. I will keep you posted.


02-19-2011, 05:03 PM
This is what I came up with. This is some of my interior fabric I had left. Put momma on the sewing machine to kind of hold the whole panel together. Tight friction fit with a couple tabs of velcro at the top. Worked out well.


02-19-2011, 11:48 PM
Looks really good!!!