June 28, 2010
NSRP project means savings in Navy tank coating costs
NSRP (the National Shibuilding Research Program) has managed to persuade the Navy to make changes in NAVSEA painting and cleaning requirements that promise to substantially cut the cost of many Navy tank painting jobs.
Prior to these changes, maintaining the relative humidity in a shipboard tank or void space at a maximum of 50 percent from the start of surface preparation to cure of the topcoat, as required by NAVSEA Standard Item (NSI) 009-32, has been a significant cost driver in tank painting.
A project team, led by Elzly Corporation for the NSRP Surface Preparation and Coatings Panel, explored a number of concepts to reduce the cost of this requirement while maintaining the high quality required by the Navy. As a result of the project, the requirement to maintain 50 percent relative humidity was relaxed to a less stringent 85 percent requirement for the following four situations:
Recoating chain lockers and Collection, Holding and Transfer (CHT) tanks
Components painted in a shop for later installation in a tank
Small areas of "touch-up" work
The period of time between cure-to-touch and full cure
NSRP says the changes will have an immediate impact on the cost to paint Navy tanks where dehumidification is required due to the ambient relative humidity. In U.S. shipyards, ambient relative humidity is below 50 percent only about 10 percent of the time. However, if painting can occur when relative humidity is as high as 85 percent, most shipyards can paint 80 percent of the time without dehumidification equipment. Dehumidifying paint shops to meet the 50 percent requirement can require millions of dollars worth of equipment. Allowing surface preparation and painting at 85% relative humidity obviates the need for such equipment and the energy to run it. In the dry dock, dehumidification equipment results in cost and space constraints. The ability to move dehumidification equipment before touch up and full cure is completed means less equipment is needed for a series of tanks.
These changes will take effect in the FY2011 version of NSI 009-32.