Question
I have a Unisaw table and a Delta shaper table that sat in storage for about a year under a roof that leaked. Both pieces of equipment have significant rust with a little bit of pitting here and there. They are unusable as is, so I need to get them functional again. Can they be resurfaced? Anyone know the cost of that compared to buying a new table? Any suggestions would be appreciated. I'm pretty upset and frustrated with myself and the landlord over this.
Forum Responses
(Solid Wood Machining Forum)
From contributor S:
You can remove the rust, even if it's real bad, by a hand lapping process. First, scrape off the loose rust with a putty knife. If you have any deep gouges, drill some tiny holes in the gouge and then fill it with Liquid Steel, JB Weld, or similar. Allow the patch to fully cure before going on.
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.
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.
