Chapter 18 - Section 9

Engine Mount Reinforcement

Carving the Urethane Foam

Since the TB aft corners has a slight curvature to it, it was a bit difficult to shape the foam for a good fit. Here's what I did...

I taped a strip of fine sand paper (6"x 10") along the aft end of the TB. I took a chunk of scrap urethane foam and rubbed against it (up/down and rotation motion) until the corner of the foam conforms to the aft corner of the TB. Then I removed the sand paper and did a final shaping and trial fit on the foam with some slight touches.

Once completed, I took a razor blade and trim the foam block to the triangular shape per plan. My triangles turned out to be ~5" long on both sides - so that they look symmetrical.

Glassing in the Foam Wedges

I microed the foam wedges in place per plan and made up 10 6"x12" BID for the engine mount reinforcement. Due to all the odd surfaces and edges at the corners, I expected challenges in getting the BID to lay down nicely. Therefore, I took time to smooth out all the corners and wedges with sanding and micro before hand. In addition, I wetted out all the BIDS separately, then laid them down one at a time. Less challenging than expected and they turned out nicely. I peel plied both sides and let cure overnight.