when I was younger I tried to sharpen some wally-world cheapies on a grinder
end result was a trashed blade and a ruined heat treat
doesn't seem like much but the $10 or so I paid for it meant alot to me back then
learn to sharpen free-hand and if you cant do that try out the spyderco sharpmaker
I'm was very good in sharpening with a stone but since I own S77 and INFI metal-type knives, I've never been able sharpen "razor-sharp"... Maybe because the metal is stronger than the popular stainless steel or because of the geometry? dunno.
