I removed the tube and doubler from the pant, trimmed the excess epoxy & Aerosil and overlapping carbon with the die grinder and then sanded smooth. I then cut a door from the second batch of doublers and trimmed to fit the hole.
When that was done, I laid up five layers of carbon sandwiched between two layers of PVA'd ally foil, the back riveting plate, a top plate and a bunch of weights. This should make a nice flat sheet from which I can later cut hinge parts for the door.
