With the backer plate cured overnight, the water weight and peel ply were removed. The four locating holes were match-drilled to the backer plate to ensure correct alignment, then the backer and packaging tape was removed from the cowling.
I diverted from actual assembly work to design the hinge for the access door. After about 1.5 hours of CAD work, I had a design that seemed to work, so full scale 3-view drawings and unfolded drawings were printed. These were glued to aluminum sheet as a cutting guide. Another 1.5 hours, and the hinge assembly was finished. It would have taken less time, but I inadvertently made the first piece from 6061-T0, far too soft. Fortunately I discovered it before it was completed, and I had enough 6061-T6 on hand to make it correctly.
The door was cut from the cowl using a fine tooth blade in a Jig saw. The door and the opening edges were sanded smooth.
The backer plate was clecoed in position and marked for the interior cut. It also was cut with the Jig saw then sanded smooth and clecoed back in place.
