I finally fixed my helmet visor after 14 hours of sanding over 3 weekends
So I built a Mandalorian helmet out of EVA foam and got the whole thing looking decent until the visor. The problem was my first visor was a clear sheet of plastic from a 2 liter bottle and it kept popping out because the foam edge wasn't flat. I spent about 6 hours just sanding the eye slot with 220 grit and then 400 grit trying to get a straight line. Every time I thought it was flat I would hold it up to a lamp and see a gap on one side. I went through 3 visor attempts, one of them cracked when I tried to heat shape it with a heat gun in my garage in Boise. What finally worked was taping sandpaper to a flat tile and dragging the helmet across it instead of using my hand. That took 20 minutes and showed me exactly where the low spots were. Anyone else run into a visor that just will not sit flush no matter what you try?
Dragging it across a flat tile is the move, hands always lie to you when you sand curves. Sanding the visor for 6 hours by hand was never gonna fix a wavy edge anyway.