I have a cheap tool with some rust on it. It's probably cheaper to buy a new one than to clean it. But I wonder if is there any solution where I can drop it and retrieve it clean. Is there anything like a rust solvent?
Perhaps naval jelly would (Phosphoric acid) do the trick? Or maybe electrolysis…
This stuff is sick: http://www.evapo-rust.com/
I used it on a drill press my buddy left out on a patio in the rain for a year. Virtually no scrubbing. I don't understand how this is not one of the most widely known products in the world. It is THAT good. I guess with the military as a client, they don't need the business from the public. Here are some pics. Truly an amazing product. I purchased a gallon of it at a Harbor Freight store for $20.
In Brazil we have Semorin - Tira Ferrugem (rust remover)
SUPER EASY!!! Get a cheap nail brush (but a big one for use on feet is better, if you're willing to sacrifice it), toss your tools in a tall cup of baking soda (don't measure, dump in as much as you think you need and a little more) with some water. Take out one piece at a time and go to town scrubbing on top of a good hand towel. Keep going until it's as clean as you need it to be.