Patched my 3" Darkstar payload tube after relocating the camera. I decided to add a patch even though I filed the holes simply because this is the payload bay and is subject to pressure from the deployment charges.
Sanded the inside of the tube for better adhesion
Cut the patch, I only had carbon fiber. I like to leave a very thin boarder to prevent fraying, which can be removed after and does not inhibit the CF from absorbing the epoxy.
Applied some tape to a sheet of clear mylar just to keep it in place once inserted into the tube
Applied epoxy to the front of the patch then transferred it to the mylar then made sure the epoxy had full coverage on the backside
Rolled the mylar and inserted it into the tube
Mylar inserted and patch pressed flat to work out as many air bubbles as possible. Tape wrapped around the end of the tube to prevent mylar from moving
Inserted a balloon to apply pressure while the patch cures
Mylar removed and patched sanded and feathered out
Wiped on then wiped off a thin coat of epoxy to smooth it out no rough edges to catch on the chute, it added minimal weight and all finished