3/26/2009
HEADLINES
Skiles at SEFA: Corrosion Ups Costs

More than 24% of corrosion could be eliminated with hot dip galvanizing, Paul Skiles told the Southeastern Fastener Association.

Skiles, vice president for sales & marketing at Tennessee Galvanizing, showed a photo of corroded fasteners on the 1903 Williamsburg Bridge in New York City that carried more than 100,000 vehicles and trains per day before a $750 million repair.

“Zinc protects steel,” Skiles declared. “Zinc is a barrier protection.”

Excerpts from Skiles’ presentation at SEFA:

* Many users expect coatings to be bright and shiny but the reality is that zinc dries to a dull grey. “I get that call all the time,” Skiles acknowledged.

* Painting over galvanizing increases the life expectancy. Skiles showed the White House gates as an example.

• Zinc rich paint is known in the industry as “cold dip galvanizing.”

• Some galvanizers have customers bringing in even stainless steel for galvanizing.

* Zinc mechanical plating is done by tumbling fasteners or other small parts in a drum. The process does “not necessarily coat completely,” Skiles acknowledged.

* Hydrogen embrittlement is “now rare,” Skiles declared. Coatings manufacturers occasionally receive complaints about hydrogen embrittlement.

* Galvanizing can be RoHS compliant.

* Skiles said hot dip galvanizing “doesn’t produce hazardous waste.” The Tennessee Galvanizing plant in Jasper, TN, recycles all acid. The processed crystal waste is used in animal food and fertilizer.

High grade zinc is very low in impurities and toxic metals such as lead, Skiles said.

The Tennessee Galvanizing plant is surrounded by a ditch and berm to prevent storm water runoff problems.

The company is ISO 14001 and 9001:2000 certified and has been awarded certificates for Hazardous Waste Management and the 2008 Environmental Excellence award by the Tennessee Chamber of Commerce and Industry.

* Avoid galvanizers using a chromate quench system, which can be hazardous to employees, customers and end users. The SEFA audience cringed when Skiles mentioned an example of a developing-nation galvanizer responding to a question about employees not wearing eye protection by saying, “We hope he doesn’t burn both eyes.”

* The biggest problem areas are thin coating at corners and edges.

Hot dip galvanizing dates back to 79 A.D. with the first records of zinc use. The first known U.S. galvanizing plant was established in 1870.

Related Links:

• SEFA