Removing Rust from a Table Saw
Start off with sandpaper on a 1/4 sheet palm sander. Keep the sanding wet with mineral spirits. Use whatever grit it takes. Sand for a bit, then clean the surface real well with pure alcohol or similar. Then lay a straight edge (Starret makes good ones) on the table and shine a small bright light at the gap between the straight edge and table. Mark your high spots with a grease pencil and keep sanding with extra action on the highs. When the table starts looking good and you have it figured flat, then start going to finer grits. 200, 400, 600, 800. Examine the top after each grit with a bright grazing light under a magnifier. This will reveal any remaining sanding pits. Keep checking with the straight edge for flatness.
Finally, polish the top for an extended period using a cerium oxide type polishing compound. Polish for a long time. You'll end up with a beautiful, smooth top that's flatter than new.
From contributor D:
The easiest and best method of rust removal is by electrolysis. I've done this to old antique tools found at flea markets that looked worthless, and with very little effort came out sparkling like brand new. I'm not going to go into detail here because there are many step by step tutorials all over the web.
Basically, I can see it may be some more effort in your case, but less than sanding it. You'll need to unbolt those heavy cast iron tops and set them in a large tub that they can be completely submerged in. I'm thinking a kiddie pool or the like. You hook the negative end of a battery charger to your table, and the positive to a sacrificial anode of choice, like an old piece of rebar, and do not let them touch each other. A little baking soda in the water is needed. Plug it in and leave it. The ionized rust will be bubbling toward the anode. Every now and then, unplug it and brush off loose rust with a grey scotch brite pad, and move the anode around. The bigger the anode is, the faster it works. Anyway, it will remove all the rust completely, which you really should do before filling any pitting.
I've only done this in a five gallon bucket, but I'd not hesitate to do it in your case. There are folks out there who professionally restore antique cars who've knocked up a plywood box lined with a tarp in order to soak a whole rusted car frame. Much less work than sanding through all the grits, and also does not risk removing any of the base metal, just the rust. The drawback in your case is the weight. If you don't have a cherry picker, shop crane, or at least a couple strong backs, then trying to do this alone would be a bear.
From contributor J:
Both my thicknesser and jointer had surface rust. 3M Scotchbrite and WD40 seemed to polish it up alright.
From contributor S:
Google Unisaw restoration and you'll find some really good articles on it. There's a good video series, too.
From contributor F:
Like to find out more about electrolysis. check the web for Coolerman FJ 40. It's about restoration of a Land Cruiser.
From contributor J:
I have the exact same saw with the same bit of rust and I cleaned it up quick with a little kerosene and fine steel wool. Of course all shop machinery not in regular use will develop some rust on the horizontal surfaces. Routine table-top maintenance is all part of maintaining your workshop. Anyway, don't make a federal case out of this unless you have to… Then you can dip the whole dang thing in an electrified bubbling vat, along with the FJ40. (I'm currently looking for some old junk to try this out on. This looks too good to be true.)
From the original questioner:
Mine is far worse, with some pitting. I have been cleaning it with WD-40 and a 3M pad and have been making progress. Thanks for everyone's help.
From contributor E:
If you're trying to restore it, I'd certainly dig up some info at OWWM. On the other hand, if you're looking to get the rust off and use the machine to work, I'd hit it with some WD40 and a ROS fit up with a Scotchbrite pad and get it done quick and dirty. Pitting won't affect the way the saw works, so I wouldn't worry about it.
From contributor O:
Take the four bolts off that secure the table to the cabinet and take the top to a shop with a Blanchard grinder. For just over a hundred dollars they will give you back a cast iron mirror.
From contributor N:
WD40 and a scruffy pad (Scotchbrite). Wet Scotchbrite it! Been there. It works.
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