Pete: Generally, adding solvents/gasoline/etc to waste oil is a big no-no. Some places I take my waste oil will actually smell the oil to ensure it has not be mixed with gasoline/solvents. So, what to do with it? I also use mineral spirits in my parts cleaner which is located outside. I do an initial fill whenever I have large cleaning projects and then let evaporation empty the tank before I clean it up waiting for the next project. Once the level goes below the pump, I simply dunk the parts, brush, dunk, brush, and so on. I do the same with my spray gun cleaning solvent. I clean my guns in a 5 gallon bucket and let evaporation get rid of the solvents. The paint stays in the bucket and hardens.
With that said, I know the environmentalists are not happy with my approach, but luckily there are no laws against what I am doing in my area.
