In light of my last post regarding the heat barrier, I realized I made a mistake in materiel choice for the patches I made for the firewall. I used aluminum sheet stock, whereas I should have used galvanized steel to match the material of the firewall. Aluminum melts at ~1200°F, while galvanized steel is good up to 2000°F, which is the FAA requirement. I cut new patches from 26 ga. sheet and reinstalled rivets and rivnuts. In addition to the rivets, the patches are bonded to the skin with JB weld.
Yesterday I received the replacement firewall insulation, Thermo-tec aluminized heat barrier. It’s definitely more substantial than the foil-faced foam sheet supplied with the kit. It appears to be similar to the material that is supplied with the firewall-forward kit for wrapping around hoses that pass near the exhaust manifold. I’ll repeat a burn test and post the results.