The last major task on the fuselage canoe was getting the forward belly skin in place. That, in turn, meant mixing up some nasty, gloppy Flamemaster CS1900 firewall sealant to seal the firewall-to-skin joints.

This stuff is a pain to work with…it has a consistency something like taffy, and it doesn’t adhere very well to stainless steel. Its only redeeming characteristic is that it’s one of the few sealants capable of withstanding the 1000 deg F temperatures the firewall is supposed to protect us against in the (hopefully extremely) unlikely event of an engine compartment fire.

Before troweling this stuff on, I un-clecoed the side skins and pulled them back to expose the firewall side flanges.  I also pre-positioned the belly skin just above the firewall (big thanks to Mike Bullock for posting his sealing process, I copied it verbatim).  The blue painter’s tape is there to keep me from making a complete mess of everything else behind the firewall.

This stuff doesn’t spread well…if you don’t apply a lot of pressure to smooth it out, it stays “lumpy”, for lack of a better word.  Here’s what it looks like when applied…it’s actually smoother than it looks.

Here’s the final result, with a few side rivets set for good measure.

More riveting tomorrow…