Fiberfrax on interior firewall

Rick_A · #1 06-08-2008, 09:05 AM

So yesterday, I spent most of the day covering the cabin side of the firewall with Fibrefrax http://www.aircraftspruce.com/catalo.../fiberfrax.php

I used the Fiberfrax cement as the adhesive.http://www.aircraftspruce.com/catalo...axadhesive.php

While I was applying the cement, I noticed that when it dried it was quite brittle. Now that I've got it all on, I'm concerned that the brittle nature of the dried product means that it will start cracking, fall off and make a big mess once it is subject to normal vibrations during flight.

Has any one else used these products? How do they hold up over time?

RV8RIVETER · #2 06-08-2008, 09:32 AM

Ceramic fiber insulation is brittle and very "dusty". I personally, would not want it in the cabin. Having used 2300deg ceramic wool for my pizza oven, it is also considered a carcinogen. Your material may be different, but then again maybe not. Here is the MSDS for one type of fiberfrax.

http://www.fiberfrax.com/files/Fiber...MSDS-M0001.pdf

Make sure you look up the MSDS for the exact kind you have. Probably a good idea to seal it off with some other material if you decide to use it.

az_gila · #3 06-08-2008, 11:20 AM

I believe it's usually used on the firewall side of composite planes (Rutans) and as a heat shield on the inside of composite cowls (our RVs) near hot engine components. I've seen them hold up well in these two applications.

Since it's usually bonded onto a fibreglas substrate, I'm not sure that your installation on the cabin interior bonded onto metal will stand up over time.

The best thing would be to contact the manufacturer.

It could be sealed with an epoxied layer of glass cloth, but that would not help with the long term adhesion to the stainless steel firewall.

gil A

Rick_A · #4 06-08-2008, 01:55 PM

Gil, after seeing your reply I decided to test the adhesion by removing a small piece. I wasn't terribly surprised when I found it came off quite easily.

I removed the rest of it - most of which came off pretty easily. Now I'm in the process of scrapping and cleaning off the places where the cement stuck well (not a lot but I'm sure it will take a few hours).

So this leads to the next question: What material is good for use on the cabin side of the firewall?

Bugsy · #5 06-08-2008, 02:11 PM

Visited the Cessna plant last month, they used fibrafrax on the interior firewall for the columbia. Doesnt mean its the exact same as what you purchased but the concept isnt unreasonable either.

Ken · #6 06-08-2008, 03:27 PM

Quote:

Originally Posted by Rick_A

Gil, after seeing your reply I decided to test the adhesion by removing a small piece. I wasn't terribly surprised when I found it came off quite easily.

I removed the rest of it - most of which came off pretty easily. Now I'm in the process of scrapping and cleaning off the places where the cement stuck well (not a lot but I'm sure it will take a few hours).

So this leads to the next question: What material is good for use on the cabin side of the firewall?

http://soundexproducts.com/

Ken

az_gila · #7 06-08-2008, 05:18 PM

Quote:

Originally Posted by Bugsy

Visited the Cessna plant last month, they used fibrafrax on the interior firewall for the columbia. Doesnt mean its the exact same as what you purchased but the concept isnt unreasonable either.

...but..but.... isn't the Columbia fibreglas?

Fibrafrax works great on composite surfaces... and can be encased with a layer of glass on top of it...

It was the adhesion to stainless I queried.... and apparently, it doesn't...

gil A

rzbill · #8 06-09-2008, 06:45 AM

Once I saw the results of an RV inflight fire. (Not me, thank goodness). The stainless firewall did it's job, but the aluminum skin under and around the pilots feet (tandem RV) was GONE. I will likely put a layer of fiberfrax that starts up the firewall a couple of inches and is a continuous strip extending under the rudder pedals and rearwards about a foot or so. Planning on capturing it with a cover of some sort. Sound insul maybe.

Of course, I reserve the right to change my mind.

CNEJR · #9 06-09-2008, 07:27 AM

After looking at Soundex, and deciding their kit was a little pricey for me. I used a product called Dynamat. I read all the specs, did a burn test, etc. It came out quite well. They make a version for cockpits. I used two layers of 1/4 inch and sandwiched to layers of tin foil, one layer of bubble wrap between the layers between. When applying a torch to it, it self extinquished immediately, when removed. I used 3M adhesive to bond. Biggest job is to cut and fit cardboard templates for firewall sections. I found this setup to be very light.