My company makes window balances. One of the parts of this balance is a metal spring. When the spring is compressed and expanded it can make a "boing" sound. The spring is compressed when the window sash is raised and expanded when the sash is lowered. Is there a painting process that can help quiet these springs?
The spring is made of two types of metal: phosphorous coated music wire (ASTM A228 and A228M specifications) and hard drawn galvanized steel wire (ASTM A227 and A227M). J.W.
Sound dampening coatings are generally soft and elastomeric and, in the case of a spring coating, it must also be extremely flexible. Nearly 50 years ago, when I was an industrial paint consultant in training (one has to start somewhere), my company applied a plastic cement to the inside of steel electrical equipment cabinet panels to keep them from vibrating and "drumming". The coating acted as a vibration damper. That coating would be too rigid for your application. My first suggestion would be coating the springs with a flexible polyvinyl chloride powder or liquid coating. Another candidate would be an elastomeric polyurethane coating. In either case you will need to apply a primer. Most of the other polymers are too rigid. The springs must be cleaned to remove oily soils before coating.