This step is making a triangular piece of spruce to mirror a section of the lower longeron so that a box area can be formed next for the landing gear mounts.

First shaped a box length of spruce to a triangular shape and then cut notches as done on the lower longeron so that it would bend and fit without too much tension.

Then a trial fit as it is an awkward shape. Alternating clamps, side then top, worked well. I didn’t bother with nails this time.

Then flox both sides into place, clean up and leave to cure.

Prepare piece

Trial fit

Flox in place