The main gear bulkhead is a structural component which the main landing gear attaches to. This bulkhead gets reinforced with two layers of BID.

Inside of the cabin looking aft. Just in front of the main landing gear is the Main Gear Bulkhead. The gray that goes halfway around the bottom is structural epoxy that holds the bulkhead in place for now. At the bottom on either side are two chases (or channels) that will be used to run electrical cables to the engine compartment. The two cutouts in the center of the bulkhead are where the cables that retract the landing gear go through the bulkhead.

Close up of the left, center and right of the bulkhead.

The first task is to create a fillet with a “micro-slurry” (epoxy with microscopic bubbles called “micro-balloons” that thicken the epoxy). This rounds over the intersection where the bulkhead meets the fuselage. Then the two layers of BID are applied.

View of bulkhead after the micro-slurry fillet and BID layup. You’ll notice that instead of gray, the joint at the bulkhead is now yellowish. That’s the micro-slurry.