The cowl came with a fiberglass oil door that does the job just fine. However, this door is designed for use with a plain hinge and camlock 1/4-turn fasteners. I plan to use a flush hinge and latch, but for the fiberglass door to work it would need reinforcement since it is too flexible. Rather than go through all that, I decided to just make the door out of aluminum. I cut out an oversize stip of 0.063 and went to work refining the shape to match the cure of the cowl. 0.063 is not all that easy to bend. I had to work it quite a bit to get the righ shape. The tool that worked best was a gap in my workbench. I could slide the piece into the gap and slowly bend it into shape. The end result fit great after trimming.
I went ahead and made a flush hinge from some piano hinge and 0.032. However, I think the 0.032 may have too much flex, so I may redo it in 0.040.
A while back I bought a camlock push-button latch. I had to space the latch out from the door by 0.063 to account for the thickness of the cowl. I also made an aluminum strike-plate for when the latch will contact.
Before I could install the door I had to build-up the fiberglass next to the door cutout so there was a flat surface for the hinge to attach. I filled the low area in the cowl with flox, covered it with peel-ply and a sheet of wax paper. I then clamped some aluminum on top of that. Once cured it left a perfect flat surface that required little sanding to finish.
