HereIt may never wear off, but soft material may clogged it. How would you clean it?
Very good hint - I will give them a try....I learned about Permagrit tools from modelboatyard.com and have used them ever since. Recently I saw a set of "Japanese finger files" in a Lee Valley catalog and bought the set. They're similar to Permagrit tools but are only 3 1/2 inches long and use finer grit. I got two flat (one tapered) two convex (one tapered) and a 90 degree file. Since they're smaller and use finer grit they're very handy in places you couldn't use a Permagrit and they leave a nearly finished surface. Look at them. Many wood model builders will like them a lot,