Tin-Zinc as a Replacement for Cadmium - plating methods at Burbank Plating Service - Brief Article

Automotive Finishing, Fall, 2000 by Andy Scheer

A perfectly manufactured part will look inadequate if the plating finish is not of the same high Quality...

Burbank Plating Service Corp. (BPS) is well aware of the impact of first impressions. Not only is the plating the first thing noticed on a part, but the plating process is usually the last operation performed. When the material is late, the manufacturing department is backlogged, the heat treater takes a little too long, and the parts are late, now is when great service from your plater is essential.

BPS was established in 1965 in Burbank, California. In 1970 it moved to a larger facility and specialized in volume zinc and cadmium plating. This put it directly in line with the plating needs of many of Southern California's large fastener manufacturers and distributors. In its 31 years, it has provided plating service for companies such as Cherry Rivet division of Textron, Binder Metal Products, WCL Co., Century Fasteners, ITW Medalist and AVK Industrial Products, among others.

BPS now operates a state-of-the-art, 20,000-sq-ft facility in Pacoima, California, providing plating services to the western half of the country. The plant houses two fully automated barrel plating productions lines. These computer-controlled lines can each produce up to 40,000 lbs of plating per day. BPS is the largest source for cadmium plating on the West Coast and is one of the largest zinc platers and one the areas prime sources for tin-zinc alloy plating.

BPS is owned and operated by brothers Andy and Robert Scheer, who purchased the business in 1985 from their father Jack Scheer and grandfather Art Barr. Since 1985, Andy and Robert have built upon the company's reputation for providing outstanding service and quality to its customers. "Many finishers provide zinc plating. The key to our success is providing a higher level of service day in and day out for the manufacturers and distributors who have built their businesses providing that same higher level of service. We pay attention to our customers' needs and respond with whatever is necessary for them to make their commitments," stated Robert.

Much of BPS's business had been servicing the aerospace industry's cadmium plating needs. Aerospace led the nation in quality control for many years, so BPS elevated its level of quality above the normal commercial plating houses to meet its customers' needs. In accordance with this philosophy, it has a full time chemist on staff equipped with a full analytical laboratory that allows for complete control of all of its processes. BPS also uses x-ray fluorescence technology for measuring plating thickness. The advantage of this technology is that it allows plating to be accurately measured at any point of a part, including recesses like threads and inside drive holes in the heads of fasteners. The data is then provided to BPS's customer in a statistical format for SPC records.

Now that automotive manufacturers have picked up the quest for the highest quality products, BPS has caught the attention of the big three automakers. BPS processes are approved by Ford, General Motors and DaimlerChrysler. Because of the automakers' search for a cadmium replacement, BPS is now providing them with tin-zinc plating, which out performs cadmium in accelerated corrosion tests. This alloy consists of 70% tin and 30% zinc and is yellow chromated for increased protection. First developed in Japan, many of the Japanese automakers have adopted this finish. BPS is now providing this finish to the aftermarket automotive products market as well as OEMs. It provides more than 1,000 hours of salt spray resistance before red rust in a 5% neutral salt spray test. It has superb solderability due to its tin content. It is a superior finish when the part will need to be formed or bent after plating, such as in the case of a rivet or threaded insert.

Cadmium has had a toxic label put on it, and most of Europe, Asia and now many U.S. companies refuse to have parts coated with cadmium. Japan prohibited the use of cadmium many years ago and has done most of the research into cadmium replacements. Cadmium plating has many outstanding qualities that have been difficult to duplicate, the most important being high corrosion resistance. Contrary to the hype, cadmium plating is still easily available and is safely applied by platers.

Zinc alloys were developed to provide alternatives to cadmium plating. The zinc alloys all have many excellent features, but none of them seems to be a perfect replacement for cadmium plating. Tin-zinc alloy plating seems to be better in many aspects. Tin-zinc offers superior corrosion protection, even after the part is crimped or bent, as in the case of a threaded insert or a rivet. AVK Industrial Products, the world leader in threaded inserts, has embraced this plating finish that enables it to offer an extensive product list featuring outstanding corrosion resistance. Tin-zinc also has excellent ductility and solderability, as well as high resistance to salt and acidic environments.