Claude Dupuis replies: I use steel wool and a combination of 3-in-1 oil and WD-40. Steel wool it on and wipe dry. If the surface will not be used for a time, apply a light coating of 3-in-1 oil and do not wipe dry.
Richard Oedel replies: Rust is ferric oxide and is not able to be converted back into iron. But you can convert it into another type of more stable state, but it won’t look as pretty. Look up online for “Best rust converters” or “best rust removers.” In general, however, nothing is going to work as well as removing the rust entirely and then sealing the naked steel. You have to seal the steel or iron from both oxygen and moisture, so a quick spray with something like Bostik GlideCote (used to be called TopCote). But keeping a low moisture environment is the best.
Bill Taylor replies: Maybe I have just been lucky but if I perform these procedures I don’t get rust. I do dehumidify my shop to 50-60% primarily for the purpose of minimizing wood movement and better finish drying. I would like to go lower but the shop is divided into rooms so that the heavy machines don’t benefit much. I do pretty consistently wax the beds, rails, etc. just because things slide so nice then and I think really hinders the rust problem. Waxing semi-annually is probably enough.
Incidentally I have never encountered any finish problems with the unfinished project wood sliding on a waxed surface. Use the same wax you would over a finish. To remove any rust I would use WD-40 and 0000 steel wool, then dispose of the steel wool pad.
Bob Couch replies: Peter James mastered the method of using Simple Green and Scotchbrite pads (green) to remove most if not all of the rust before using bowling alley past wax to protect the surface. I use the wax twice/yr on all of my cast iron machine surfaces.
Michael McCarten replies: For flat surfaces I will use flat blocks with emery paper lubed with a light oil (WD-40…etc.), until the surface is clean. If there is pitting I generally do not go into that except perhaps hitting them with a wire brush prior to the sanding. I do not want to damage the flatness of the surface by going deep enough to remove the pits.
On irregular surfaces I will use wire brushes primarily, again with light oil.
For preservation I made my own paste wax. Being an instrument maker I don’t want to risk silicone and other “foreign” materials getting onto the wood causing problems with finishing later on. I use a raw flake carnuba wax (Highland Hardware if I recall) and dissolve it into turpentine using a double boiler. Caution—do this outside for adequate ventilation and No Flame for the heat source to avoid ignition. Low and slow is the rule here. Stir frequently and adjust by adding more of either as required.
In my experience the final product will be a bit “flaky”, but it is quite usable. Rub it on, let dry, buff off. This leaves a nice hard (for wax) surface. I find one application lasts years for some tools. Others need occasional replenishment. I suspect this is due to the alloy. If you are not concerned with contamination, a good auto paste wax would probably suffice although I cannot attest to that.