I have a boat load of old files of all sorts and grades. I get them at garage sales very cheaply because they are frequently either oil clogged or rusty. You can sharpen files cheaply too. Clean the file up with some kerosene and a wire brush to get rid of as much crud as you can. Dry them off. Get a heavy plastic trough (old Tupperware, wallpaper water tub, small fish tank, etc.) big enough to lay the files flat and not touching each other. Lay some cheap dowel’s across the bottom so the files aren’t laying against the bottom the put the files on top of the dowels. Get plain old sulphuric acid from a battery supply shop (exide, battery world, etc they always have extra on hand and it’s usually very cheap.). Fill the tub with acid until the files are drowned and keep a half inch of acid above the top of the files. Cover and let set overnight or maybe a bit more depending on how cruddy they were. When you take them out, wash them with a baking soda/ Water solution to neutralize the acid. Try them out, if they need more, wash them in water and put them back into the acid. If they’re sharp, wash in water and put them somewhere warm to dry thoroughly. Obviously, you should use rubber gloves, safety glasses and common sense as you only get issued one set of eyes. How it works is that the acid eats away at all surfaces evenly so as it eats away it removes metal from the two vertical sides that make up the “ tooth” of the file and the point (cutting edge) sharpens. It also eats any old crud and metal out of the grooves giving new filings a place to go. Sorry for the overly long post, but it’s a good thing to know and saves money. The more money we save the more rifles we can have.
