Re: Removing painted letters
I may be excommunicated for saying this, but I was in a hurry to remove an old name before re-launching my boat. I used some VERY course sand paper (not sure of the grade, but I'd bet I was the only one in the yard using it above the water line) with plenty of water, and removed the worst of it in a matter of minutes. The vinyl letters had been removed before sanding, but the gelcoat had a very obvious raised edge and discoloration where each letter had been. After sanding, the old letters were virtually invisible unless I stood at just the right angle to the sun, and even then it was just a matter of a different gloss where they had been.
I'm not suggesting a particular method as much as I'm saying that sometimes you just have to pick something that's effective and get it done, unless you're trying to win a boat show or something.