I just cut a piece of 1/4 Lexan this afternoon I had laying around to reinforce the soft rear floor on my Scamp
16 under the water tank
Someone did a sloppy job of applying caulk to the Belly moulding on the outside. I picked up a piece of scrap Lexan and the sharp edge took the caulk right out and it didn't hurt the fiberglass Gelcoat at all.
I would avoid metal tools if possible