In a recent issue of PF, I read your comments on the dampening of sound on springs. I thought of a product that I recently saw applied to springs by a unique process. With this process, parts are quenched in a water-based coating directly out of heat treatment, stress relieving or tempering (whichever is last in the process). The coating is deposited as part of the quenching. The amount of the coating deposited can be controlled by controlling the solids in the quench tank. Many spring manufacturers already use the process as do some tool manufacturers (shovels, hoes, rakes, hammers, pry bars, chisels, screwdrivers and drill bits) and agricultural suppliers (plow shares, sweeps and discs). I have seen parts go in at as much as 2,100F (for sweeps) and as low as 300F (for shovels). Most springs go out of the stress-relieving ovens at 450-600F. In a way, it is a "poor man's" electrodepositon, where the heat already in the part replaces the electrical charge. B.R.
Thank you for the heads-up. I am always interested in hearing about new products and processes. This one is cool (excuse the pun). What you described sounds like an excellent way to apply a corrosion resistant coating to springs. I'm not too sure that it will dampen sound.
Speaking of corrosion on springs reminds me of a story. In 1984, I drove my daughter to a full service tire shop to pick up her car. The car was nowhere to be seen. When we inquired at the service desk, the manager popped his head around the corner and said, "The car is on the rack with the new tires installed, but I want to show you something. Look at the rust on those springs." I told him those springs were rusty three years ago when the car was new. I told him to lower the car so that we could pay our bill and get out of there. Two weeks later, I bought new tires for my car. My daughter drove me to the tire shop to pick it up. When we arrived, there was my car on the rack. Before the manager could give me his rusty springs pitch, I said to him, "I guess you don't remember me?" He lowered the car, and I paid the bill and went on my merry way rejoicing. The moral of the story is: Rust happens! To combat rust today, OEMs are using everything at their disposal to stop it.