Aug 14, 2021     Firewall       Category: Fuselage

May 2021. Firewall will be fab'd out of .026 galvanized sheet steel sourced from the local sheet metal shop. I started with a piece of 3/4” MDF cut to shape and drilled to fit the engine mount holes of the fuselage. The sheet steel was cut 3/4” oversize around the perimeter and bolted to the MDF form, The firewall plan includes some stiffener ribs to provide some rigidity to the otherwise flimsy sheet. To form the ribs I cut grooves in the MDF with a router. With the sheet positioned and secured to the MDF, the ribs were formed with a 1/2” round pipe and a sizeable hammer applied with vigour.
Ear protection preferable for this procedure.
Next step is to bend a right angle flange around the perimeter of the firewall. This requires some relief notches at the corners to get around the curves. The corner notches were backed up with a 3/4” metal strip that was tin soldered in place on the inside of the corners.