Q. I am the machine shop supervisor for a company that makes indoor exercising equipment. Some of the component parts are electroplated while others are painted. We buy these parts already painted since we have no painting equipment in our shop at this time. We are interested in setting up a paint line for our steel parts that will be a fast-acting process. We want this process to give the steel a durable black or gray finish. The paint will be applied on hardened steel parts. The two types of pieces are ½ inch in diameter by one inch long, and one inch in diameter by one inch long. We want to paint 10,000 pieces per week with a black or gray color. P.L.
A. Since the hardened steel parts you intend to paint are numerous and relatively small, I suggest you paint them using the dip-spin method. In this method small parts are loaded into a basket, and the basket is lowered into a circular tank of paint where the parts are completely coated. The basket is raised above the liquid paint level and rotated rapidly. Centrifugal force causes the excess paint to be thrown from the parts onto the side of the tank where it flows back into the tank. This is an excellent and well-proven method for painting small parts. I recommend pretreating the parts using an iron phosphate which will improve paint adhesion. Suppliers of this equipment can be found on PFonline.com.