Original Date: 05/23/1994
Revision Date: 01/18/2007

The implementation of the powder coating process at Naval Undersea Warfare Center (NUWC) Division Keyport will eliminate volatile organic compound emissions and the lead exposure hazard to painters from the spray process. The new process will apply an epoxy powder to provide up to 10 mils of coating thickness.

Prior to the application of the powder, the parts are cleaned in a batch cleaning unit using a water-based soap solution. The parts, are then packed and placed on a conveyor system, and transferred to the oven for a first pass to preheat the parts prior to the powder application. They are then passed through the dual Nordson powder booths where powder is manually applied. A second pass through the oven cures the powder coating. The oven features separate chambers for each pass to maintain different temperatures while conserving heat. Color changes of the powder can be accomplished by wiping down the booths, purging the hoses and guns, and changing powder supply drums.

Substantial performance benefits were realized from the preliminary testing of torpedo shells painted with the powder coating process. The powder coated torpedo shells can withstand 10 test firings before touch-up painting is required. Shells painted with the conventional spray process required touch-up after every firing. Material costs associated with the painting process have been reduced from $1.28 per square foot to $0.25 per square foot by the implementation of powder coating.

For more information see the Point of Contact for this survey.