Vinyl manufacturers and marine service providers contend with discoloration caused by a bacteria.
“Pink” brings to mind a little girl dressed as a princess, cotton candy at the county fair and plastic lawn flamingos. But for those in the marine industry, the word takes on a sinister connotation as a stain caused by streptoverticillium reticulum.
It’s a far greater menace than a never-washed red garment laundered with white fabrics, because vinyl pinking is a by-product from the aforenamed bacteria feeding on the plasticizers (phthalates) that impart flexibility to PVC. And while you can bleach a pink-stained towel or T-shirt, streptoverticillium reticulum is a tougher customer.
“Pink stain” or “pinking” has been identified as a problem arising in conjunction with government restrictions on the use of arsenic as an antimicrobial agent.
The original version of ASTM E-1428 dates back to 1999. Marine Fabricator has published articles on pink stain—the subject behind E-1428 and experts have talked about it at Industrial Fabrics Association International (IFAI) expos. Boat owners and marine fabricators frequently see it. Nevertheless, pinking remains a poorly understood condition.
In fact, pink stain itself is a bit of a misnomer, as the discoloration on boat cushions that it describes also can appear purple, brown, blue, orange or yellow. It is a by-product of a microorganism that thrives in dark, hot, humid conditions—like the inside of a boat cushion under a cover.
“Some people in the marine industry are educated about it, but most do not understand what it is or what causes it,” says Ed Skrzynski, owner of Marco Canvas & Upholstery in Marco Island, Fla. “I have heard so many explanations of what it is and what causes it. It really depends on who is getting and giving the information. Most often, we find it is a boat dealer and end user not knowing it is a bacterial by-product, and they tend to push the blame back to the original equipment manufacturer and even vinyl manufacturers. The end user assumes their cushion cover is bleeding onto their vinyl upholstery, which is reinforced by their actions. When they uncover their boat after a period of time, they see a stain. So they clean it and the exposure to UVA and UVB rays eliminates it. After it is covered again, the stain comes back. Using intuition and deduction, they assume the cover is staining the upholstery.
“Even when we show them documents from universities that it is bacteria, they are dubious,” Skrzynski adds.
“It’s a serious issue for some vinyl manufacturers. However, we don’t seem to be fielding as many calls in regard to it, and that could be a matter of the marine industry being better educated about it. Fabricators are now more aware of the need to choose higher-quality products,” says Mike VonWachenfeldt, technical service manager for Glen Raven Custom Fabrics LLC of Glen Raven, N.C.
“It is serious as far as people buying new $160,000 to $200,000 boats,” says Mike Charpentier, manager of Paul’s Custom Canvas in Denver, Colo. He concurs that boat owners assume pink stain is a color transfer between materials rather than the result of a bacteria.
“I have to explain to them what the problem is and how we try to take care of it,” he says. Paul’s Custom Canvas inserts a SoftTouch® felt barrier between the cushion foam and vinyl upholstery.
“It’s not foolproof, but it helps,” Charpentier says.
“Whenever pinking occurs, it can be very painful for the fabricator. The most valuable asset that the fabricator has is their reputation,” says Tim Niehaus, president of The Miami Corp., a marine fabric and component distributor in Cincinnati, Ohio. “How they handle the situation will have a direct effect on their reputation.
“A few years back, we saw a spike in pinking cases,” he continues. “A good portion of that could be attributed to new regulations. Europe was first to ban the biocide that had been used in marine vinyl: arsenic. As companies made the move away from arsenic, they learned that their formulations for a new biocide [4.5-dichloro-2-n-octyl-4-isothiazolin-3-one] were not strong enough. They quickly reformulated, but that is not to say they have been able to put an end to pinking. I’m not sure you will ever be able to do that, though there is hope that technology might give us a solution.
“The pinking issue is really the food source for the microorganisms. Remove the food source—plasticizers in the vinyl—and you remove the problem,” he continues. “Many companies are looking at options such as thermoplastic olefin [TPO]. Unlike PVC, TPO does not use plasticizers. Plasticizers are a food source for the microorganisms that cause pinking. I have seen TPO alternatives come a long way over the last few years, but don’t expect the same hand that you get from PVC, because it simply is not there. We have looked at several TPOs and have yet to find one that we believe is a good solution.”
Bill Marriott, owner of Extreme Upholstery Design in Summerville, S.C., buys vinyl from only two suppliers. He had a solitary case of pinking years ago, but recalls hearing about a class-action lawsuit when a boat seat manufacturer got sued over pink stain and, in turn, sued the vinyl manufacturer. But he doesn’t know the outcome of the lawsuit.
“Out of the blue, all conversation stopped [with the company owner],” Marriott says. “He doesn’t want to discuss it.”
“Nobody can put their finger on every piece of the pie that makes pink stain happen, consistently or not consistently,” says Justin Jones, owner of SewLong–Custom Covers in Salt Lake City, Utah. “I have been told [by other marine fabricators] that they can use the same roll of vinyl on two boats and one will pink and the other won’t.
“We have been putting a felt liner, SoftTouch, on the inside of covers to create a barrier that, so far, seems to be working.”
“We have been educated about pinking since 2008,” Skrzynski says. “Once we found a vinyl manufacturer we never had problems with, we stuck with them.”
“You really need to inspect a vessel for any signs of pinking before providing a cover or reupholstering,” Skrzynski says. “I have found you can more easily see pinking with polarized sunglasses. I add a polarized lens cap to my camera to document as well. If we find it, we note on our estimate that the customer has existing pinking and send them information on it so they know what it is. We provide a caveat in the sales agreement that if the mold grows or comes back, they agree to hold us harmless.”
Marco Canvas & Upholstery will warranty against pink stain if the customer agrees to a full scrubbing that includes replacing foam or putting it through an autoclave boiler steamer and scraping the backing board and wiping it down with bleach. But, Skrzynski says, “Most customers won’t do that because the $5,000 job they were looking at is now more like $10,000.
“We have tried everything you can think of to try to eliminate pinking. The only product that we found works is Pink Away.”
Marco Canvas & Upholstery tested the chemical in 2013 when it was only a topical treatment—before it was developed by Gestalt Scientific Corp. as a system that involves a Halotron™ device that uses a powerful, narrow-spectrum light and heat to penetrate the chemistry through the vinyl. (See tab.)
The Miami Corp. also has tried Pink Away.
“It does remove the stain and effectively prevents it from coming back to that spot,” Niehaus says. “The system requires an investment. Whether or not it would be a good investment would be a decision that the fabricator has to make.”
Janice Kleinschmidt is a writer and magazine editor based in San Diego, Calif.