Firewall Sealing

[gkalin]

OK, so what's everybody using to seal Firewalls on New construction? The Plans Say "Tank Sealant". But I see Van's sells a Firewall Sealant on it's website...……...for about 6 times the cost. With that material it's going to get pretty expensive if you have to need a small amount hear and there, depending on your rivet schedule. Just wondered what other people are doing.
Jerry

RV-14 #601
Tail 100%
Wings 100%
Fuselage 20%

[bkervaski]

We used 3M Fire Barrier 2000 - https://www.aircraftspruce.com/catal...SABEgKfqPD_BwE

Don't forget the bottom outside corners, there's always gaps between the firewall and the fuse and if you get an oil leak .. well .. loose oil likes to "explore"

[N804RV]

I would think any MIL-S-8802 equivalent sealant would do the job.

[DanH]

3M FireBarrier 2000 has held up very well, 10 years now.

[gkalin]

Thanks guys.
Jerry

[coffeeguy]

I am using the 3m firebarrier too. It was about $40 on your favorite website. The issue, though, that I'm having is that I can't get it to come out of the tube to finish off the sides of the firewall. I guess I should have built faster. I used foil tape on the top and also put it in a gallon ziplock bag and squeezed out the air. I put it in my caulking gun and pulling the trigger won't do anything except squirt out the back because I'm pulling too hard. I ran a long drill bit thru the tip and reamed it out, but it won't come out.

I read ahead and I think I've got everything identified that needs sealing. The brake fluid reservoir and the fuel line were the main ones. When I get a block of time I'm going to cut open the tube and stuff it into some large syringes and use it on everything that needs it. If there is any left I'll put in a ziplock baggie and squeeze out all the air and then double or triple bag it. It probably won't work, but why not give it a try?

[David Z]

How does 3M Fire Barrier 2000+ compare to 3M Fire Barrier 3000? Both are silicone based, have the same 4hr fire protection rating, smoke rating and sound rating. The only difference I can see is 2000+ has a specific movement rating where 3000 has a water tight rating.

Fire Barrier 3000 does have a 6x expansion volume when exposed to heat (660*F). I suppose that could cause a problem, pulling a riveted joint apart.

The other big difference is 2000+ is 3.5x the price before shipping and 3000 is available locally.

[Cwood2000]

I was considering using high temp RTV, any reason not too?

[DanH]

Originally Posted by Cwood2000

I was considering using high temp RTV, any reason not too?

Not if your airplane happens to be orange.

Seriously, the red and orange sealants work fine, but they seldom look good. Instead pick up some Permatex Ultra Black, or Loctite 598, which is the same thing (Loctite owned Permatex for a while). Dark charcoal in color, sticks to aluminum very well, shrugs off oil.

Should work fine in the firewall seam, although my go-to there is FireBarrier 2000 because it is intumescent. Definitely the good stuff for baffle sealing.

http://tds.henkel.com/tds5/Studio/Sh...EN&plant=WERCS

https://www.permatex.com/wp-content/.../tds/22072.pdf

[Bavafa]

Fire Barrier 2000 is about $40 and a qt of proseal is about $60.
The Fire Barrier is in a tube that once opened, not sure how well can be sealed for future use whereas the proseal can be used for small amount as needed. There are a number of locations that proseal is called for so it may turn out cheaper in a long run.