Monday, January 9, 2012

New Paint May End Color Mismatch of Some U.S. Navy Ships

"Haze gray and underway" has been a mantra of U.S. Navy warships for decades, and the sight of a sleek warship sliding across the ocean has stirred many a sailor's heart.
THE CRUISER SAN Jacinto shows the effect of the current paint used on U.S. Navy ships, and how it often dries to different shades of gray. (Christopher P. Cavas / Staff)
But a lot of those greyhounds of the sea start looking a bit poorly up close. Various shades of haze gray appear as patches of dark gray, light gray, tannish gray. Here and there might be patches of green-gray. Sometimes, if a ship has received a lot of touch-up work, there might be a dozen or so different grays.
Worst of all, some parts of a ship might not appear gray at all but look downright pink.
"What you are noticing is indeed true," admitted Mark Ingle, the Naval Sea System Command (NAVSEA) technical authority for paint.
"The way the pink happens is a function of time, weather and ultraviolet radiation," Ingle said. "There are an infinite number of variations on the pink theme, depending on the conditions."
The phenomenon has existed since the mid-1990s, when heat-reducing paints, called low solar absorbance (LSA) paints, were introduced. The pinking problem arrived with the LSAs and, ever since, ships' crews have struggled to keep their floating homes looking spiffy.
But help is on the way. A new type of paint is being introduced fleetwide, and before too long, the Navy hopes, its ships will regain their luster, sailors will find it easier to keep their ships looking smart and some money can be saved.
The new paint - "Type 5" in Navy-speak - is called polysiloxane.
"It's basically an epoxy-functionality paint with siloxane groups grafted on that make it extraordinarily resistant to chalking, weathering degradation," Ingle said.
In English, please? a reporter asked.
"It's an extremely hard, wear-resistant coating," Ingle explained.
The new stuff eliminates the pinking problem, he said. And if it gets scuffed or banged up, it's designed to be cleaned, not repainted.
The new paint, Ameron PSX-700 from PPG Industries, Pittsburgh, was developed as an anti-graffiti coating and, rather than painting over rough spots, the Navy hopes that eventually most stains will come off with a power-wash.
Several ships have tested the new paint, including the amphibious ships Ponce, Kearsarge, Boxer and Bonhomme Richard, cruiser Antietam, aircraft carrier Nimitz, and even the museum battleship Missouri at Pearl Harbor, Hawaii.
The new paint, Ingle said, "supports the fact that the Navy has moved toward less repainting, longer service life, longer docking intervals."
The polysiloxane is "very good for the environment, with very low volatile organic compound levels. And they are very popular. Ships want to use them all the time.
"We are in the process of these being the required paint for use in the Navy to avoid the pinking problem and save the money of having to repaint because of cosmetic color shifting of paints," he added.
But unlike the old silicone alkyd paint that comes in a can and is stirred, the Type 5 paint comes in two cylinders that are squeezed together to mix polysiloxane and epoxy glue.
"We have these two cartridges, like a double-barreled caulking gun," Ingle said. "The cartridges are fitted together and squeeze out into baffles, which mix the paint so that it comes out as a properly-mixed product ready to be applied. It uses a gun similar to a caulking gun."
Ships in overhaul availabilities already are getting the new paint, he said, and fleet technical manuals are being updated to include procedures and policies for using the cartridges.
"Sailors have never had a two-pack topside paint before," he noted, but "eventually everyone will have the two-pack systems."
The paint is available from three manufacturers: PXLE-80 from Sherwin Williams, PSX-700 from PPG and Interfine 979 from International Paint.
The new Type 5 paint costs roughly twice as much as older paints, Ingle said, "about $70 to $100 a gallon for the new paint, versus about $30 to $60 a gallon for the Type 2 or 3 LSA."
But since ships will not need to be painted as often, the paint should save money. The Office of Naval Research, working on the Future Naval Capabilities' Topside Coating program, estimates the polysiloxane will save about $153 million over 30 years.
The paint already has been in widespread use in the Coast Guard.
"The Coast Guard has been using polysiloxane for years and has had tremendous success," Ingle said. "How often do you see different shades on a Coast Guard cutter? Running rust?"
To assist sailors in using the new paint, Corrosion Control Assist Teams come pierside and provide the equipment to do a paint job.
Ingle likened it to a lending library. "The crew comes down and takes out what they need - five needle guns, two grinders, etc," he said.
A major goal is to minimize the amount of paint carried on a ship, said Stephen Melsom, NAVSEA's program manager for fleet corrosion control.
"There are hazards associated" with paint stowage, Melsom said. "I'd like to go from them having this paint locker and just having touchup kits if you will. So when you need the touch-up, they can inject it from the twin-tube system. Get away from all that stowage on the ship."
NAVSEA is working with the Naval Research Laboratory to develop a new, low-pressure, electrically driven power washer to clean polysiloxane surfaces.
"We're not talking about washing the entire ship at one time but a portion of the ship," Melsom explained. "Take a power washer with a brush scrubber, not that different than what you'd use at home on a deck, to get the salts off."
A corrosion control manager is also being designated aboard each ship.
"It's typically a senior enlisted sailor," Melsom said. "They're getting trained, and they'll be taught on polysiloxane and other things they need to do to make corrosion control a way of life."
The new paint is proving extremely popular, Melsom reported.
"Ships are asking where they can get it. They understand there is a difference," he said. "And when you see the difference between the new paint and the old paint, it's pretty evident."

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