I built the firewall following the plans with one exception; I followed the approach outlined in the Sportsman 2+2 manual where the flange tabs sit aft of the firewall. This creates a cleaner seam around the periphery of the firewall at the flanges and allows the fire blocking sealant a cleaner bead.
I had fashioned an acrylic firewall template and then transferred that template to the stainless sheet and pass-drilled the mounting holes. Initially, cutting the firewall and the holes was slow-going but I eventually got the knack of it with the shears and made quick work of it.
I had already built the firewall a year or so ago but managed to rivet it all together after only test-fitting the sheet inside the fuselage end forward of the cage attach points. Once assembled, the stainless steel flanges exceeded the tapered front of the fuselage. This was a major setback for me, but also a learning opportunity.
For the latest firewall, I was cautious to fit and re-fit at each step of the way. In the end, the final firewall is built way better and even includes an "engine turning" swirly pattern like some vintage aircraft finishes I've seen. (The Spirit of St. Louis being one of them). For fire protection and temperature control, I installed FiberFrax and Cool Mat on the cabin side
Read on in additional posts for how I laid out the components on the firewall and set the attach points for each item.
