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How much 3M Fire Barrier 2000?

ppilotmike

ppilotmike

Well Known Member
For those who have gone before:
I'm planning to build my firewall similar to what Dan Horton did (i.e. fiberfrax insulation on the engine side, sandwiched by another very thin sheet of stainless foil/sheet). I need to purchase some tubes of the 3M Fire Barrier 2000+ silicone sealant to seal everything up. Anyone have an idea of how much I will need?
 
FIREWALL INSULATION

WHAT ARE THE OTHERS USING ON THE INSIDE OF THE FIREWALL THESE DAYS AND HOW IS IT ATTACHED?
 
Regarding inside of the firewall - Search DANH's posts. My plan for the inside of the firewall is nothing. Insulation will go on the engine side of the firewall. DANH's research and posts have me convinced. Why risk it for marginal benefit.
 
bruceflys said:
Aircraft Spruce sells a ceramic blanket with the stainless layer already attached. http://www.aircraftspruce.com/catalog/appages/firewall2000.php?clickkey=62571
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Bruce,

I believe my sandwich of materials (i.e. 1/8" thick fiberfrax sandwiched between the SS firewall and another 0.010" sheet of stainless steel) will hold up better against a fire. The material you suggested only has a max temp rating of 1,000 degrees, which might not be enough. It sure would be interesting for Dan H. to do a test on his fire rig of this material though..
 
One more question..

When riveting together the firewall, should all the rivets, angles and brackets and such be "wet set" using a fire barrier sealant?

Seems like there could be leaks (i.e. carbon monoxide leaks) from an area under pressure (engine compartment) and the cabin if not sealed up. However, Vans doesn't mention sealant in the instructions, at least not during the building of the firewall itself...

Confused.
 
I wondered about this too... What I'm going to do is run some 1/2" wide 3M #433 aluminum tape (-60 - 600F temp range) over all the flush rivets on the engine side of the firewall before laying the fiberfrax and SS sheet. That should provide an airtight seal for 99% of the firewall, leaving only the nutplates and passthroughs as potential leak spots that can be sealed in other ways, like with firebarrier. The 600F temp limit means it should never come close to failing until there' a pretty serious fire that has already penetrated the first couple lines of defense... and the rivets themselves that are covered up by it won't be far behind in failing at temperatures above that.

As for sealing *everything*... I'm not sure if it's practical or even possible to make the firewall be "100%" airtight and burnproof, although of course that is the ideal goal. I think what we're doing (as Dan's testing seems to support) you could probably call 95-99% and that's about as good as we're gonna get. I think it's more robust than the majority of other light aircraft out there, that's for sure... including certified.

Now I'm sitting here scratching my head, thinking why did I not mask off the inside of the firewall when I did interior paint... :mad: I'm trying to decide how big a deal it is to have paint on it and if it's worth going to the effort of stripping it off now. Aargh.
 
mikeyj350 said:
I wondered about this too... What I'm going to do is run some 1/2" wide 3M #433 aluminum tape (-60 - 600F temp range) over all the flush rivets on the engine side of the firewall before laying the fiberfrax and SS sheet. That should provide an airtight seal for 99% of the firewall, leaving only the nutplates and passthroughs as potential leak spots that can be sealed in other ways, like with firebarrier. The 600F temp limit means it should never come close to failing until there' a pretty serious fire that has already penetrated the first couple lines of defense... and the rivets themselves that are covered up by it won't be far behind in failing at temperatures above that.

As for sealing *everything*... I'm not sure if it's practical or even possible to make the firewall be "100%" airtight and burnproof, although of course that is the ideal goal. I think what we're doing (as Dan's testing seems to support) you could probably call 95-99% and that's about as good as we're gonna get. I think it's more robust than the majority of other light aircraft out there, that's for sure... including certified.

Now I'm sitting here scratching my head, thinking why did I not mask off the inside of the firewall when I did interior paint... :mad: I'm trying to decide how big a deal it is to have paint on it and if it's worth going to the effort of stripping it off now. Aargh.
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Thanks for the reply Mike. The tape is a good idea, and much easier than trying to fay seal everything with fire barrier sealant. Where did you buy it?

As far as your painting goes, I would think you could use a solvent to remove the paint that's there, but yes, it will be a pain. Give yourself some motivation by buying a nice bottle of something to have once it's all done; the cost of which will be your cost of education. :D
 
Ha! Not a bad idea. :D I agree, it is probably worth it for me to take the time to do that. I have a can of Rustoleum Aircraft Stripper, I assume that stuff will be up to the task.

The 3M 433 tape is a little pricey, but I bought mine a month or two ago from ULine as they had it on a kind of overstock sale.

Just checked again and it turns out it's still on overstock... quite a bit cheaper than anywhere else I could find:
http://www.uline.com/BL_6471/3M-433-Aluminum-Foil-Tape

Cheers!
 
mikeyj350 said:
Ha! Not a bad idea. :D I agree, it is probably worth it for me to take the time to do that. I have a can of Rustoleum Aircraft Stripper, I assume that stuff will be up to the task.

The 3M 433 tape is a little pricey, but I bought mine a month or two ago from ULine as they had it on a kind of overstock sale.

Just checked again and it turns out it's still on overstock... quite a bit cheaper than anywhere else I could find:
http://www.uline.com/BL_6471/3M-433-Aluminum-Foil-Tape

Cheers!
Click to expand...

Sweet! I just ordered a roll at the discount price. Thanks.
 
ppilotmike said:
When riveting together the firewall, should all the rivets, angles and brackets and such be "wet set" using a fire barrier sealant?
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No. The quantity of gas leakage past a set rivet is way, way way down the list of things to worry about. Main sealing concern is any open holes created by fluting around the structural firewall perimeter. That's why you run a filet there before applying any insulation or foil.

mikeyj350 said:
What I'm going to do is run some 1/2" wide 3M #433 aluminum tape (-60 - 600F temp range) over all the flush rivets on the engine side of the firewall before laying the fiberfrax and SS sheet.
Click to expand...

Points for thinking, although it is overkill.

Now I'm sitting here scratching my head, thinking why did I not mask off the inside of the firewall when I did interior paint... :mad: I'm trying to decide how big a deal it is to have paint on it and if it's worth going to the effort of stripping it off now. Aargh.
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Depends how well you breathe smoke.
 
DanH said:
although it is overkill.
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Agreed I suppose, but I think there's probably one or two folks out there who would think an extra layer of SS and fiberfrax could be considered overkill too ;) why not add a few more ounces of tape and really make it airtight?

And I'm an ex-smoker, so I guess maybe I can breathe smoke better than others, so I'll keep the paint :p just kidding, it's on the to-do list to strip it.

Thanks again guys!
 
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mikeyj350 said:
And I'm an ex-smoker, so I guess maybe I can breathe smoke better than others, so I'll keep the paint :p just kidding, it's on the to-do list to strip it.
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Mike,

Maybe you could work it out with Dan to have him burn a sample, while you inhale. Hey, empirical data, man! :D
 
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