Washing Steel, Aluminum and Plastic Parts

Question:

We are purchasing a new stainless steel parts washer. It holds about 2,500 gal of water heated up to 180F. The machine does NOT have a rinse stage. It does have a heated blowoff for drying. The machine has a galvanized belt and some mild steel parts but is predominately stainless steel. We plan on washing steel parts (bearing races, bearings, stamped panels, etc.), aluminum parts and plastic parts. The parts are mainly contaminated with light oil, transmission fluid and dust. We need one solution that will clean these various parts while leaving them spot free and rust free. In addition, the solution must not attack the machine. Do you have any suggestions? D.F.

Answer:

It does not sound like you have a very difficult cleaning job because no-rinse cleaners are typically very light-duty in nature. That is also good news for the washer and the parts you need to clean since these cleaners are near neutral to slightly alkaline and will not attack any of the materials you mentioned. The near-neutral cleaners are very similar to dish detergent, except that they use low-foaming surfactants in a spray washing application. Those cleaners that are slightly alkaline may also contain a small amount of builder (a complex phosphate) and possibly an amine (such as triethanolamine) that will also provide a short amount of in-process rust protection. You are fortunate that the cleaning is relatively easy. More difficult cleaning prior to painting would necessitate a more highly built cleaner that would require rinsing. I suggest that any washer purchases first be developed and validated around the cleaner and cleaning process. Many chemical suppliers will be able to simulate cleaning of your parts in their labs.