Many of you may already be doing this and I have found it to be a real time saver. You can usually pick up one of these at a yard sale for cheap. Throw in 10 - 12 old bolts/screws, fill halfway with sand, plug in and walk away. A day or two later you can dump out the contents onto a sheet of newspaper (anyone still get those?) and seperate the hardware. Usually you only have to blow it off and you have metal that is ready for paint!
1 part sulfured (animal feed grade) molasses to 9 parts water. Toss the iron in and let chelation remove only the oxidation, no loss of "good" metal. (you can leave stuff in for days, weeks, years...) Basically the same chemistry as Evaporust, at 10% cost. (But it is an outside activity, cuz it can be a bit odoriferous.)
I just use Evaporust. I have been using the same 5 gallon pail for years. It is reusable. Just drop the rusty parts in and the next day, no rust.
I use Evaporust as well, usually larger parts. I really like it and have the same 5 gallon jug from years ago as well. The tumbler cleans off dirt as well which I have to do before using any solution, so that saves one step!
straight white vinegar works great too, but it will etch metal and flashes over very quickly when dried.
