Dan, Let me share this chatter and general concensus from another composite homebuilt community. (I can't recall which one anymore ;) Just sharing what I read and I'm not smart enough to comment on it myself.
One poster.... " I have thought about the use of SS for firewall protection and this seems to be a good idea because the SS effectively stops flame penetration. The one major drawback of SS is weight. There is a product called 'Stainless tool foil wrap' It is used to wrap steel parts for furnace heat steel part treatment to exclude air. It is .002 thick and comes in 2' by 50' rolls. This material can stand up to 2100 degrees F (Type 309 or 1800 degrees F (Type 321). 20" x 50' $155 or $115. If a fiber fax and thin aluminum sheet (Maybe aluminum in front of the SS). is used as backup it could be a lighter less costly solution. One roll of this material would make at least twenty firewalls. This product would stop the flame pentration and would save about 5 lbs in weight over the .018 thick stuff. (A aluminum sheet backing would still be needed however.) The SS could be sandwiched between the alumium and fiberfax or it could be glued to the face of the aluminum." Regarding insulation... They had at least one actual nail-biting engine fire where the followng was tested. The fire burnt thru where the RTV wasn't. - For insulation it's: fiberfrax - For insulation-firewall adhesive it's: "High-temp red RTV silicone from the auto-parts store. The stuff, itself is very resistant to flames and heat." Specific comments include... - "Do not waste your money on the special adhesive they sell for the fiberfrax. It is useless(as an adhesive and fire suppressor). Red silicone is much better." - "RTV is much more expensive than the adhesive provided with fiberfrax" - "You will need 3or4 tubes to put the fiberfax on the firewall." - "trowling that stuff on for 100% coverage to bond the fiberfrax on and then to bond a stainless firewall to that. Aluminum is pretty much useless there, decorative at best." Another poster.... "- Cut to shape the fiberfax for the firewall, - Cut circles out of the fiberfax approximating the engine mount washers about 1/4" in diameter larger, - Apply the silicone, then the fiberfax, then the SS firewall material. - Now use a bolt the size you would use for the engine mount. - Put a washer the same size as the one used in manufacturing the mount (foot) (that goes to the firewall) on the bolt. - Stick the bolt through the stainless steel through the firewall hole , washer the inside, nut it and draw it down tightly. - Do that for each of the 4 mounting holes for the engine mount. - Let the silicone harden. - What this will do is to compress the stainless steel, under the engine mount feet, directly on the firewall with no fiberfax underneath it and bevel (to none) the stainless steel from the thickness of the fiberfax, underneath it. - You will then have a good contact surface between the engine mount and the firewall, (throgh the stainless steel, rather than having a compressible material (fiberfax) between the mount feet and the firewall, which may possibly continue to compress and possibly cause future looseness. - Remove the bolts and bolt on your engine mount." Tom --- On Sun, 6/27/10, Dan Heath <da...@windstream.net> wrote: From: Dan Heath <da...@windstream.net> Subject: KR> Firewall Stainless To: "'KRnet'" <kr...@mylist.net> List-Post: krnet@list.krnet.org Date: Sunday, June 27, 2010, 8:13 AM
