I play bass violin for a living. I was watching a repairman fairing the ebony fingerboard on my instrument. He was using pane glass: scoring it with a glass cutter, and breaking off pieces. Using a small piece of glass as a scraper, he would take lovely little slivers of ebony off. After a few minutes of use, he would toss it and break off a new piece.He could break off pieces that were straight or curved. Has anyone tried this technique on boats? This guy is one of the top repairman in the country and does a whole lot of scraping.