Renewing rusted table saw tops

How to fix a badly rusted table saw top in a few easy steps. February 7, 2001

We were sawing heavy last week and did not make it to the wood shop. Apparently I left a piece of wood on the table saw, and the top rusted, in a 12” x 16” area. The scale is so heavy the top can not be seen. Now what?

Forum Responses
Try a very light sand with 600 grit automotive wet-or-dry sandpaper, then wax the surface.

Squirt some WD40 on it and start with coarse to medium sandpaper, then use fine sandpaper to make it shiny again. Last put a good coat of Johnson’s paste wax on it. It worked for me.

The ideas above are very effective--I like naval jelly and WD-40.

One of the problems with rust is that the iron, when it combines with oxygen to form rust, actually swells slightly. So when you remove the rust--iron oxide--the bare metal that is left will be slightly shallow, accounting for the iron that has been removed. In severe cases of rust, it may be necessary to add some material to fill in this slight depression, or else have the entire surface re-milled so that it is perfectly flat.

Gene Wengert, forum technical advisor

From the original questioner:
I used 600 grit and our PC random orbit sander. The rust came right off and showed no pits. I put a straight edge on the surface and could not see any depressions.

Use floor wax only, never automotive wax or polish, as they contain silicone. It will ruin the finish on wood. I prefer a monthly application of Bostik TopCote table top sealant--it makes sawing safer as very little pressure is required to move the wood, and it is less likely to make a slip.