That pretty much sums it up. Today we deburred the stainless firewall, then bent the tabs on the left and right sides of the center firewall. Since there is a step from the firewall to spar, we bent down the edges to provide protection to the edges of the plywood firewall and make the transition from firewall to spar. While I was working on that, Greg prepped the firewall by sanding it.
Next we used RTV, which is a high temperature sealant/gasket maker, to bond fiberfrax to the stainless firewall. Fiberfrax is the actual protection for the structure of the firewall and spar. It is a thin cloth that is an insulation and provides temperature resistance. Then there is a layer of RTV over the plywood firewall that bonds the other side of the fiberfrax to the airframe. The layers of RTV were squeegee-ed onto the surfaces to use minimum material and minimize the thickness build up.
Lastly, a bead of RTV goes around the perimeters and seams in the stainless. This prevents any oils or other debris from getting to the fiberfrax and deteriorating it. The technique is basically like applying household caulking. Don’t look too closely at this, I apparently have not mastered the art of caulking. Don’t invite me to caulk your bathtub!
I didn’t take a lot of photos today, but I did get some of the final product. It doesn’t seem like this should have taken all day, but it nearly did.
The Garaggio was such a mess, I had to do some cleaning. Still much more to do.
the Garaggio 