As a hobbiest, I do not have the same option such as a service that changes out the parts washer solvent. I have a 20 gal parts washer with with a electric pump and sprayer. In the past I have used paint thinner as the solvent. A local paint supply store sold the thinner in bulk (at $2/gal, the price was right) and the evaporation was not too fast. Now I have to buy the paint thinner at retail.
At the other end, disposing of the dirty solvent poses a problem for me. Lately, I have been thinking that if my solvent were say kerosene or diesel (an oil) maybe I could dispose of the dirty solvent with the used oil that my local autoparts accept for free. I do not want to be the person that "contaminates" the used oil bin.
I have also been thinking of adding an engine oil filter between the pump and the sprayer, not sure that the pump has enough power to push the solvent thru a filter. If it works, I might not need to change the solvent for many years.
I know that there are water based solvents (Simple Green, etc) out there. Question is, how does one dispose of the water based solvent
- I could flush it down the sanitary sewer - but does that not cause potential issues at the water treatment plant (I presume that there is still oil in the water emulsion)?
What do you do? WHat do you suggest?