I have several 3" x 5" scrapers size +/- I managed to sharpen them the first time but since then I have not had much success. I have put them in a vise and filed them down and tried to redo them, just not satisfied with the results. I use them to flatten turned surfaces on my lathe, they work better for me than anything else. but I have them all dulled so that they are pretty much useless now. Yes I have followed the instructions, on how to sharpen, Any thoughts