Thanks Deejay, I thought it was a stone, not a file. It isn't usual to oil files because it makes it more difficult to clean the swarf out from between the file teeth, but it does contribute to a better finish if you do it. Whether you oil it or not, getting a good finish requires "carding" the file every few strokes. Unfortunately it is more or less impractical to use a standard file card on the Buddy, but there are substitute techniques for keeping the teeth clear.
