Using a blast cabinet can abrade the sharp corners of the machined holes for the backrod, feedscrew bearing holes, feed gear bearing holes, mandrel bearing hole, and set screw holes, etcetera. I put wooden dowels in all of the machined holes and sacrificial screws into the set screw holes. I always start with walnut shells and only move to other abrasives when there is stubborn paint.
When doing sheet metal the use of walnut shells is standard since other abrasives can blast right through the metal before you realize what damage you have done. Walnut shells make the process of removing material much more accurate than other abrasives which can remove a lot of material very quickly. With regular abrasives you can create dips and valleys before you even know it. Once the piece is cleaned, handle it with gloves to not get any skin oils on it. A primer coat of paint should be applied reasonably soon after cleaning. It has been ten years since I had to do this to a basket case machine so I know I am forgetting things about the process. It is good that you are practicing on a more common piece first. Best wishes, Al _______________________________________________ Phono-L mailing list http://phono-l.org
