It has been a while, but I got back down in the garage for a good chunk of time and started removing the original panels. I don't like to speak ill of dead men, (original owner passed away,) but he sure did a number on the riveting. Panels were half-sealed with a thick and uneven layer of some type of clear caulking, uneven number of rivets side-to-side, hand-bent corners that were more like gentle radii....oh well- it will all be redone. I might do the highly visible bits like the sill runners and the bulkhead in thin brushed stainless.
I tried to vacuum the trapped rivet debris out by drilling a large hole in the end of a frame element, plugging all the other holes up with tape, and feeding in surgical tubing hooked up to a vacuum. This failed. I couldn't get large enough diameter tubing into the frame to be able to pick up meaningful bits of rivet with the suction. I am really stuck with what to do here. Cutting up the frame to get these bits out scares the heck out of me. I am looking into the foam method, and might test that on a few scraps of square tubing.
I tried to vacuum the trapped rivet debris out by drilling a large hole in the end of a frame element, plugging all the other holes up with tape, and feeding in surgical tubing hooked up to a vacuum. This failed. I couldn't get large enough diameter tubing into the frame to be able to pick up meaningful bits of rivet with the suction. I am really stuck with what to do here. Cutting up the frame to get these bits out scares the heck out of me. I am looking into the foam method, and might test that on a few scraps of square tubing.