A few years ago I got several hand saw (5 or 6) and 4 framing squares that were all rusted up.I took a sheet of plywood and nailed some 2x4:s to it, layed it on the floor of my shop and spread a layer of poly over it, put the squares and the saws ( with handles removed ) in it and poured vinegar over them. This worked out quite well until I tried to get the vinegar back into a container. I had put the 2x4's down on the flat side and when I tried to raise one end so I could scoop out the vinegar the majority of it ended up all over the floor. If I were to do this again I think if the 2x4's were on edge it would be a lot easier to clean up.