Last week I cut off the ends of the too-long machine screws that attach the coaming. About 1/2" too long, the machine screws extended down into the coaming and the ends scratched my daughter's legs when she was trying out the kayak in the pool. I used my dremel with a cut-off wheel to cut about 3/8" off of the installed screws. The first one dropped a red-hot piece of machine screw onto the seat and I realised that I had better do something to catch the cut-offs lest they fall onto the PVC fabric. The second one did the same thing and I had the same thought. The third one fell between the seat pieces and, surprise, surprise, burned a hole tight through the hull. I'm sure it would have been funny seeing me run into the house to grab a coffee cup of water and dump it (way too late to be effective) into the kayak only to have all of the water flow out of the nice clean hole melted in the fabric.
After that learning experience, I was finally motivated to prevent more holes. I used a wet rag laid out in the cockpit to catch the smoking hot screw pieces (wet to quickly cool the cut-offs and prevent the rag from burning). I also spread my cutting around a little more, cutting the screws nearly through then coming back to them later for a short final cut preventing the pieces from getting quite so hot. Once cutoff, the sharp ends of the machine screws were covered with an acorn nut.
The picture below shows the full-length stainless steel machine screws, the locking nuts, the acorn nuts and the cut off pieces, as well as the dremel with cut-off wheel.
Below, a freshly trimmed machine screw. The tube to inflate the bow flotation bag can be seen.
Below, a machine screw with locking nut and acorn nut.
The nice clean hole, about 1/4" in diameter, created by a piece of red-hot screw.
The patch to fix the hole, perhaps the last item to complete the kayak, installed this evening. The patch is about 2" by 1", many times larger than the actual hole, and is adjacent to the keel line.
By the way, the Yost-designed Sea Flea I think is now officially done. I'll take some pictures and post them soon. In addition to adding the patch, this evening I finished the outriggers. The girls and I are now working on a paddle.