The cleaning is accomplished using a variety of methods.  The cast and steel housings and  parts are baked in an oven at 800 degrees for 6 hours to burn off paint, grease, and any other contaminants.  Then they are put in a high velocity shot blasting machine which removes ashes, rust, etc. leaving the metal looking like virgin material.  They are then put in a multi-cycle washing machine where they are cleaned with a mild caustic solution, rinsed with hot water (190 degrees), and then sprayed with hot water containing a rust inhibitor.  Some aluminum and small parts are cleaned in a vibratory cleaner using a mild degreasing cleaner.  This thorough cleaning leaves housings and parts able to be easily examined by our technicians to determine if they meet original specifications or will need to be machined or replaced.