I have a grizzly grinder and it only has one speed, fast. Because of that I can really only use low grit belts. I have used up to 180 grit and those blow the temper really quickly, like really really quickly. So what I have started doing is using a hand sander to finish the blades, but even using low grit paper and spending hours one a side there are still some pretty deep scratches from the initial grinding. Is there any other way to finish a blade, or am I doing something wrong? Any help or advice is welcome.