This instructable is a general overview and comparison of different restoration techniques. The object of experimentation is a drill press. Not all steps are in detail, but information can be found elsewhere on the web for exact instructions on different techniques.
Step 1: Find a Tool to Restore
Hunt around on craigslist or other sources for used tools that people are trying to get rid of. I picked up this rusty old drill press for only $50. Know what to look for and how to bargain. I try not to pay any more than 50% of the asking price.
Step 2: Inspection
Do a general inspection of the project and start the disassembly.
Step 3: Rust Removal (Cup Brush With Oil)
I used a cup brush on an angle grinder, with motor oil to keep down the dust, on the main column. It worked pretty flawlessly.
Step 4: Rust Removal (Cup Brush Without Oil)
I tried the cup brush without motor oil on the base plate and it seemed to work just as well. There was a little dust produced, but that was better than oil splatter.
Step 5: Rust Removal (Oxalic Acid)
I tried bar keeper (oxalic acid) on the slotted table. You can see the circular area where it was applied on the first photograph. It removed some of the rust, but the angle grinder with a cup brush was much better.
Step 6: Rust Removal (Electrolysis)
Electrolysis is another option for rust removal. I did not get around to testing it until the drill was mostly finished but it works well. I run the system over night then scrub the items with a wire brush. Instructions and explanations on the set-up can be found online. It is a more complicated method than the others, but still quite simple and once you have the set-up it can be used repeatedly.
Step 7: Degreasing
I tried degreasing some of the parts. Surprisingly the best method I found was vegetable oil. With vegetable oil the grease came right off. I then rinsed the parts in dish soap to remove the grease/oil slurry.
Step 8: Painting
I sanded the surface of the orange paint of these parts and wiped with acetone. I then painted over the top of the paint with a few coats of spray paint.
Step 9: Painting
I used the angle grinder to remove the paint from these parts and cleaned them with acetone. I then laid down 2 coats of primer and 2 coats of paint. I will see how much better this painted surface lasts compared to the previous method. I also created a painting room in the basement with painters plastic so that the parts would not be affected by wind or dust.
Step 10: Nuts and Bolts
I dropped the nuts, bolts and other miscellaneous parts into a bowl and covered them with vinegar. It took about 5 days for the full film on top to from, but the method worked really well. I rinsed them with water and scrubbed with a wire brush. I then baked them in the oven to remove water. A blow torch could also be used to heat them up and prevent oxidation.
Step 11: Chuck and Spindle
I tried bar keeper and a metal brush on a dremel to clean up the chuck and spindle. The rust removal was insufficient so I went back to the angle grinder to finish the job.
After testing the reassembled drill with a dial indicator I found the chuck to be very true. The bits however showed significant run out, so there must have been damage to the teeth. I replaced the chuck entirely and the problem was absolved. The instructable is at the following link.
Step 12: Motor Disassembly
Disassembling the electrical motor was probably the most complicated step in the project. It required a gear puller to remove the bearing. Always remember to take pictures along the way. You may think you can remember how to reassemble, but it could be months before you reassemble the project. Taping or painting the wires is also helpful with the electrical. I even found a little insect nest in the motor housing.
Step 13: Paint and Reassemble
Paint the motor housing and reassemble. I drilled a hole in a piece of wood to apply equal pressure when pressing the bearing back in place.
Step 14: Paint
Paint the remaining parts. I painted them outside and brought them in to dry by putting them in a box. This protected them from dust and prevented the fumes from circulating in the house.
Step 15: Polishing
I tried a number of metal polishing methods none of which worked flawlessly. More experimentation is needed.
I first tried sanding with successively finer grits of paper. This method was OK for removing large scratches, but left more to be desired.
I used jeweller’s compound of different grits, with a buffing wheel on a dremel, next. This method definitely removed the very fine scratches, but is definitely a finishing method because it will not remove anything other than fine marks.
I tried polishing with Simichrome both by hand and with a dremel, but didn't have much luck removing scratches. It seemed to work better as a general polish. I think this method definitely needs more exploration, because from what I have read it can be used to polish scratched surfaces.
Step 16: Woodworking
The handle for raising and lowering the slotted table was very awkward and weak. I turned a wood handle on my lathe and fitted it with some hardware.
Step 17: Reassembly
This is where the photographs come in handy. Reassemble the machine with a generous dollop to grease and hit the switches.
Step 18: Complete Restoration
Use the beast in your next project.