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Firewall Sealing

gkalin

Member
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%
 
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?
 
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.
 
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/S...at=MTR&subformat=REAC&language=EN&plant=WERCS

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

It's hilarious that saving $20 would even be a consideration in this hobby.

Another thing to keep in mind is that proseal never really polymerizes completely. If you use it on cabin seals there will always be that wonderful sulphur perfume soaked into the upholstery, waiting to greet you every single time you enter the airplane.

I initially "stuck to the plans" and sealed the fuselage sides with proseal, but even months later the stench was so annoying in my poorly ventilated garage that I scraped it all out and did over with silicone.

The only downside of silicone is one must be very careful not to get it onto surfaces that will be painted. Use plenty of masking tape.
 
It's hilarious that saving $20 would even be a consideration in this hobby.

If you read carefully, my post was not meant to suggest as a way of saving $20. The original question suggested proseal can get expensive and as a result was looking for alternative.

The two RV I built which had proseal to seal the FW and the back window never had any kind of smell that I could detect but maybe my nose is not as sensitive as yours. However, I have also used silicon with great results both inside the cabin and outside without any issues.
 
I opted for 3M Fire Barrier 1000. It's ratings and certifications are quite similar to Fire Barrier 2000+ and costs a significant amount less. Plus it's available locally, so no shipping cost.

Might not be the best or ideal, but it's certantly better than tank sealant.
 
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