Got a little done on the cowl. Now I need to form the cowl extension onto it without melting the reinforcements, drill and weld through. For the spot welds, I used countersunk bores on both sides and used a piece of wood underneath so that when I pushed the ABS weld rod through, it filled the countersink on the backside with the idea being that it would work like a rivet. Unfortunately, the heat gun is overkill and a blowdryer too weak to hit a good temp for the plastic, so ]pre-heating it without overdoing it (which I did a little, hence some waviness), then maneuvering the welder and getting the weld rod into place before it cooled too much was tough, so that's why I decided to go with countersinks. I also went over the weld ends with the welder to blend it further. To clean up all the ugliness, I'm going to take the scrap ABS bits and melt them in acetone to make a filler. I read that works, but I haven't tried that particular thing before. If it does work, I imagine it would be a lot better than epoxy or body filler since things don't like to stick to ABS. Plus, it's free. I have plastic welded a little with polycarbonate (really tough), polypropylene (fairly easy), and high density polyethylene (similar to PP), but I have never tried ABS before nor this filler technique. Car bumpers and kayaks are a lot easier than this was, but I'd still take it over PC.
View attachment 159386