firewall insulation

[iowaflyer]

For starters, I've already done a search on the forum archives and haven't really found the answers I'm looking for.

I need to put insulation on the cockpit side of the firewall of an already-built RV-4. I'm mainly concerned about thermal insulation--sound proofing would be nice but isn't a priority. Any suggestions? A search turned up more info about what not to use than what to use. Obviously, flammability resistance is important.

Also, what do you guys recommend to glue it to the firewall?

[David Paule]

My 1955 Cessna has a fiberglass pad there. It's not glued, but all the various through-parts run right on through it and the threaded parts hold it in place. It must have been installed very early in the construction.

There's a clear plastic overlay, too.

Ain't fancy but it works.

[dpansier]

This thread will provide a ton of information on firewall insulation.

http://www.vansairforce.com/communit...ad.php?t=37012

[Neal@F14]

Is this stuff any good?

http://www.aircraftspruce.com/catalo...rewall2000.php

[vfrazier]

We like this stuff heat shield mat

It's inexpensive, fairly lightweight, very easy to install, and should last the life of the plane with minimal care.

We make no claims that it will stop Dan's raging flamethrower, but that's the job of the stainless firewall. However, it does help reflect heat and offer a layer of ceramic insulation to help keep your feet cool.

Bottom line: easy, cheap, durable, waterproof.

[IowaRV9Dreamer]

Originally Posted by vfrazier

We like this stuff heat shield mat

It's inexpensive, fairly lightweight, very easy to install, and should last the life of the plane with minimal care.

I'm interested in this problem right now as my firewall is finally "done". Do you recommend putting this stuff on the outside of the FW? If so, is its adhesive good enough or does it need some additional method of attachment.

Also, do you recommend putting some other material on the inside for sound reduction? If so, what would you use and how best to attach?

[mfshook62]

I recommend that you do not use vinyl plastic foam (soundproofing) material on the cabin side of the firewall. If you are unfortunate enough to have an engine fire, the black "closed cell fire retardant" foam will alert you immediately as it produces the most choking fumes as soon as it heats up, melts, and quickly starts to smoke. Now you have 2 major problems to deal with; 1. you have a fire, and 2. you can't breathe. I considered using this material for soundproofing in my 9a and decided to test it. I placed a square inch of this black soundproofing foam on an aluminum sheet and heated the backside gently with a propane torch. The foam quickly melted and then produced the most acrid and unbreathable chemical fumes that you could ever imagine. If you are considering placing foam soundproofing material in your aircraft, try the above test and then decide. In my opinion, this foam should not even be on the market as a soundproofing material for aircraft.

[flyboy1963]

I echo Mike, i did the same test, however primitive, with everything I bought.
The black foam, when encased in 2 layers of heavy aluminum foil, will still cook and out-gass. Ditto the grey rubber mat.
I used the foil faced woven fibre mat, attached with LATEX contact cement on the cabin side of my firewall, and taped seams etc. as needed with foil tape.
I'm sure this could be greatly improved upon, but it's fairly safe & effective from my point of view. I have no delusions about 'fire-proofing', I just hope i gained 30 seconds more margin from the fire.

[RVbySDI]

Originally Posted by IowaRV9Dreamer

I'm interested in this problem right now as my firewall is finally "done". Do you recommend putting this stuff on the outside of the FW? If so, is its adhesive good enough or does it need some additional method of attachment.

Also, do you recommend putting some other material on the inside for sound reduction? If so, what would you use and how best to attach?

There are several threads dealing with this issue. My posts are in many of them but I do not have time to link them to this message. Do a search on Firewall insulation and you will find them. To answer your question about whether the adhesive is good enough. I mounted the material I used on the engine side of the firewall with no adhesive except some aluminum foil tape along all edges and around all firewall penetrating wires, cables, etc. All of the various parts that are bolted to the firewall then were bolted in place. This "sandwiched" the insulation material between the firewall and battery box, brake reservoir, etc. etc. All of the various bolted components are proving to be more than adequate enough to hold the insulation material in place on the firewall.

Hope this helps.

[vfrazier]

RVBYSDI is correct. The HeatShield mat goes on the engine side. Seal it down along the outer edges with RTV or ProSeal for a tidy installation. Mount your other components as usual and they will help hold the sheet in place should the adhesive lose its grip. Remove the HSM under the engine mount points or other critical components that must be 100% tight and secure (use common sense here).

We also have FAA burn rated closed cell foam for the cockpit side. Let's be clear here... FAA burn rated means it will only slightly kill you if exposed to flame. If you're not cool with that, use something else. Good luck finding the magical material that emits no fumes when heated AND is suitable for the intended purpose.

IMHO, the intended purpose is keeping my feet cool. My parachute is how I intend to handle any serious fire.

Please don't construe my comments as flippant. In my view, this is the best compromise for MY comfort level as I hate the thought of burning up more than I hate the thought of losing a $100K airplane.

Also, hats off to Dan Horton for making this an issue that people take seriously. You should take it seriously!!! An inflight fire is your worst nightmare.