Just a quick update. It's been going well to paint over the ABS that has been sprayed with filler primer. No more scratch marks. I'm still not great with spraying gloss so some orange peel, eg on this knee armor.
However, after wet sanding with 1500, 2000, then polishing with a plastic polish + microfiber sponge, I'm getting a nice smooth gloss that should be ready for clear:
The forearm seam is much smoother after the milliput:
One small setback is that many of the seams on my 3D printed parts have been splitting. I did not plastic weld all of them, and every one I didn't weld has split eventually. I actually think it may be because I'm using acetone-thinned Bondo spot putty to smooth the surface, and I think it's eating the CA glue. So I sanded the chest and back seams and welded them, then filled and sanded with milliput:
I'll spray them with filler primer today to check out how the seams look.
One other thing I can't remember if I'd mentioned before was that a while back when I was heat shaping one of the calf pieces, I put quite a large dent in it. I was able to push it back a little, but decided not to try to use heat to fix it given the high chance of making it worse. Instead I filled it with milliput and sanded it flat. I'm fairly certain it won't be noticeable once it's primed and painted:
I've also started prepping the helmet for paint: