Look on peachtree woodworking. There is a spray product for cast iron tools that keeps them from rusting and doesn't gum up the work you are doing on it.
Franmar Saw Blade Cleaner Pint (16oz) BBBQTWD
http://www.ptreeusa.com/franmar_chemicals.htm
I have a thing of the aerosol that has lasted for years and works great. Unfortunately it's not sold that way any more.
Steven