I have a hard stone I use with a little fine oil just a couple slow even swipes every now and then will be fine just remember you have to keep the stone flat to the blade other wise you will round over the cutting edge and defeat the purpose.i thought about checking the blade angle and mount the stone some how into a jig and lock the blade in the jig and use a Diamond stone when you find a old blade that needs some real edge work. Now I use a good file to redo the edge on a draw knife that has been neglected like hanging from a old rusty nail in a old shed and not being touched for over fifteen years you know what I mean .