Another Method of Cleaning a Hand Saw
Several methods of cleaning hand saw blades of rust and coatings are published on the internet. Briefly, these are:
Scraping with a single-edge razor blade or other sharp blade at a low angle, either dry or with mineral spirits as a lubricant.
This is followed by wet sanding with mineral spirits, using grits from 220 through 1000 as needed, with or without a sanding block, possibly then by rubbing with steel wool.
Here is a method I developed that removes rust without the risk of scratches from scraping, without mineral spirits, and at a low cost.
Like the other guys, I remove the handle, and then lay the blade on a flat outdoor surface where rust stains won’t matter. I started out using an old outdoor table and now have a small Trex shelf attached to a privacy fence, similar to a gardener’s potting table.
The main tool I use is a small fine-grained whetstone or water stone. The one I started with wore thin, then broke when I dropped it, but I have picked up several replacements for $1 to $2 each at flea markets and yard sales. If there is oil buildup on the stone, I degrease it first with a water-base cleaner like 409 or Spray Nine. The stone functions both as grit and sanding block, lasts much longer than a pack of sandpaper, and is much cheaper.
If the saw blade is greasy with used motor oil, WD-40, or who knows what, I remove that where it won’t go into my soil. Then I flood the blade with water, and begin rubbing it with the stone in long lengthwise strokes. The rust comes off quickly at first, so I stop frequently to rinse the blade and stone. I stay at least ½ inch away from the teeth, preferring to keep my fingers between stone and teeth. This is both to protect the set and to preserve the stone.
I generally start on the side with the etch. If it begins to show, then I stop going over or near the etch. I work at removing the rust from the rest of that side of the blade, continuing to rinse frequently. Then I resume going over the etch very carefully and slowly. Once more of it shows, I stop and switch to the other side of the blade. When that appears to be as clean as possible using the stone, I switch to wet and dry automotive paper of 400 grit and up, still using water. Using a small pad with the paper, I carefully go over the areas of the etch that are still obscured until they start to show. At that point, I’ve learned to stop with the etch.
The paper works well to attack any stubborn rust, usually in dimples or on the toe if the saw was stored in a shed or barn. The area under the handle may show how the saw looked when it left the factory, but the area at the edge of the handle can have extra rust where the wood retained moisture. Generally the bolt holes will have raised edges, and flattening those with the stone may make slipping the handle back on easier.
One cautionary note is that the stone may have a few stray grains of larger grit that will scratch the blade, so check for the feel of that and look for it when rinsing. That won’t matter when the rust is thick, but it will if you are almost done.
Immediately after finishing I wipe the blade thoroughly dry and hang it in the sun. Then I wax it like the other guys do.
One bonus is that your rusty fingernails will identify you as an antique tool lover and the kind of guy who can answer questions at the hardware store or home center. Try bleach.
Finally, if you are polishing brass sawnuts and are a nit-picking kind of guy, use a toothpick with polish to get the crud out of the screw slots without scratching the brass.