Firewall Part 4

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.

Comparison of the galvanized steel patch (left) vs. the 6061 patch (right)
Patches re-installed

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.

Thermotec Aluminized Heat Barrier

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