FWF-Insulation glue !

[L.Adamson]

Originally Posted by mlwynn

I have thought about firewall insulation and am at the spot where it ought to be done. I was primarily thinking about keeping the cabin cooler during summer operations. Somehow, I thought the insulation was supposed to be on the cabin side of the firewall. But with all stuff being attached to both sides of the firewall, I am not sure where, how thick and how to attach. What have others done?

I'm going cabin side only. My 6A has none at the moment, but it's considerably noisier than a insulated 9A I've flown. I use ANR headsets which get rid of most of the noise problem; but the noise effects the operation of the intercom.

As far as the engine side, there is a lot of items bolted to the firewall, let alone oil, grease, etc.
I wouldn't dream of putting anything on the engine side.

L.Adamson --- RV6A

[Transporter]

I bought a yard of 48" wide firewall insulation from Flightline Interiors (see http://www.flightlineinteriors.com/p...on/default.asp).

I just cut pieces to fit between the firewall reinforcement angles; one yard is more than enough to cover the firewall.

Haven't weighed the insulation yet, but the pieces are very light. I'd guess 1.5-2.5 lbs total for all the pieces.

Next step is to give a scrap or two a burn test and figure out some attachment clips. This thread is very timely; I'll try some "L" clips as suggested by Dan.

Mike

[BillSchlatterer]

I've seen this used in a lot of cars and it is really good. Very thin but dense and absolutely stops any tin-canning. It is relatively low temp (300 degress) but I was thinking of putting it on the firewall side in some of the larger open areas to dampen the vibrations and use the two sided light stuff on the inside with high temp RTV as an adhesive. In a hot fire, fumes would be on the ohter side of the firewall.

http://www.b-quiet.com/ultimate.html

This stuff is made specifically to dampen sound and vibration. Kinda pricey

Anyone used it ? I think they actually make a package for the RV10.

Bill S
7a finishing

[Pilottonny]

Dan,

It is the insulation from flightline interiors (see mike's post) I tried to set it on fire with a lighter but it did nor burn, just melts, sort of. Good enough for me.

Regards, Tonny

[Transporter]

The firewall insulation from Flightline Interiors for my RV8 weighs in at 1lb 6oz...

I can't get it to light (yet...gonna get a hotter flame).

Like Tonny says in his post, the insulation will melt...sort of. I tried lighting it in the center of a sample (on the foil) and nothing happened under direct flame from a lighter. I then tried lighting an edge and the black felt materiel in the center melted in from the foil outer layers about 1/8", and then quit melting. The melted edge appears to insulate the rest of the felt from the flame. No visible smoke and I couldn't smell any fumes. The material also cools quickly. I could touch the foil over the melted area immediately after taking the flame away without getting burned. So far, so good.

I'll try a hotter flame (propane torch) later this week.
Mike

[DanH]

Mike,
Not much point in subjecting the insulation you describe to a direct flame, although it is good to know. It probably passes the tests outlined in FAR 25 Appendix F. For insulating the cabin side of stainless firewall, we just want to know that it doesn't make smoke or ignite when placed very near a glowing metal sheet, and that it doesn't re-radiate enough energy to drive up the temperature of nearby objects (like your feet, plastic brake fluid tubing, etc). We would prefer the above conditions for perhaps 10 minutes. Hopefully an engine compartment fire will starve for fuel by then, or you'll be on the ground. The firewall itself is required to last 15 minutes @2000F on a certified airplane.

My concern in this particular thread is about the glue. Does it smoke or ignite on a red hot firewall? Same is true of paint and other coatings. As for other kinds of insulation, I think folks who insulate the cabin side of a firewall with foam rubber, vinyl-faced, or plastic insulation are, well, in denial.

If you like, send me about one square foot of your insulation and I'll run the burn rig to see what temperature the heat target might reach with extended burn time. If it will keep you toes cool enough to walk away, I call it good stuff.

[Transporter]

Dan,
I'm with you regarding the real test using stainless.

The 'test' I did today was crude, but I wanted to see whether this stuff would burn/smoke/give off fumes before I went too far with it.

Send me a PM with your shipping address and I'll get a chunk in the mail to you for your burn rig.

FWIW, I put my palm on one side of a 6" square piece and applied flame to the other side with a lighter. It got warm, but not hot. Good insulation qualities. Some melting of the 'felt' between the sandwich occurred but the foil seems to dissipate heat well and the foil did not melt. Again, no smoke or apparent fumes.

Mike

[DanH]

Ran Mike's insulation on the burn rig tonight. Sample was held in loose contact with the stainless "firewall" using two clamp strips at the vertical edges. Burner is on the other side. Flame was pre-calibrated to 2000F at the stainless using copper foil (melt temp is 2000F). The black square is a radiant heat target six inches from the firewall. The heat target approximates temperature measured at the soles of the pilots shoes.



The sample was emitting heavy black smoke a few seconds after flipping the burner valve. It burst into flame in about 15 seconds. I dropped the Raytec and grabbed the camera. This was about 30 seconds into the test:



A few seconds later, from the "engine" side of the firewall:



The fiberous insulator between the aluminum foil sheets was rapidly consumed. The flames you see here were jetting out from between the foil sheets. The foil was mostly intact after the test, indicating a temperature at the insulation package less than 1100-1200 degrees F.

There is a very large difference between an appropriate firewall insulation and an FAR-compliant cabin wall insulation. This stuff is really, truly awful.

[Transporter]

Dan,
Thanks for doing the test.

I just looked at another RV8 project today and the builder was using the same material...I'll pass the results on to him.

So-back to the drawing board!

Mike

[Wicked Stick]

Dan,
Those are some dissapointing results. Especially since there was no direct flame in contact with it ? Only the immense heat transferred to it from the engine side caused it to burst into flames ?

Confirm please this was the stuff sold by Flightline ?
Seems like it's only good as a mild thermal insulation.

How much of a real engine fire is this simulating ?
What I mean is, how long do you think it would take before the firewall would reach the same conditions as your burn test did ?

Looking at those pictures make one think they'd be better off without anything compared to having that stuff there.