Professional BoatBuilder - December-January 2018

14 PROFESSIONAL BOATBUILDER

ROVINGS

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COURTESY NEXT TECHNOLOGIES (ALL)

Just when you think there’s nothing

new under the sun, some engineer  nds

a new way to build a mousetrap—not nec-

essarily better but undeniably di erent.

May we present: the In ated Wing Sail, or

IWS.

Swiss sailmaker Edouard Kessi has

been pushing the envelope of wings for more than 30 years.

Co-owner of the Voiles Gautier sail lo in St-Prex, he

became intrigued with paragliders and in ated textiles and

formed Ailes de K, which originated production in 1984–85.

According to Internet sources, Kessi’s business partner Lau-

rent de Kalermatten is considered the father of paragliding.

For sailboats, Kessi has long experimented with membranes

as quantum improvements over traditional sailcloth. In fact,

Wing Full of Air

Ever observe faint pink discoloration of white vinyl boat

cushions and wonder what it is? It’s right up there with

wanting an explanation for the “green  ash” that some-

times occurs when the sun falls below a crisp, clear horizon

(waiting and wondering is a popular tourist activity on Key

West’s Mallory Square). Well, the green  ash has been cer-

ti ed real and explained as the eclipse of refracted and

separated light colors, starting with the longest wave

length; and now the cause of confounding pink stain that

resists cleaning also has been revealed.  e following was

extrapolated from a short piece written by Hugh Barrett, a

technical consultant with APV Engineered Coatings in

Akron, Ohio.

First, there is a di erence between pink stain and “pink-

ing.” Pink stain is caused by the growth of microorganisms

on the surface of a “plasticized vinyl or other polymer”: spe-

ci cally, Streptoverticillium reticulum, a bacterium o en

found in soil and rotting vegetation. Sound useless and

obscure? Actually, Barrett says streptomycetes account for

two-thirds of “the clinically useful antibiotics of natural ori-

gin.” Here’s a weird piece of trivia. A er World War II the

U.S. Army experimented with streptomycin for serious

infections: the  rst patient died; the second went blind; and

the third, Robert J. Dole, was cured and went on to become

a U.S. Senate Majority Leader and a candidate for president.

Pinking, on the other hand, is a discoloration caused by

the “overoxidation of phenolic compounds commonly used

as antioxidants.”

According to Barrett, you can’t clean pink stain, because

it has been absorbed into the vinyl. Better, he says, is to think

about prevention. To prevent the growth of Streptoverticil-

lium reticulum you can apply a biocide such as arsenic (not

recommended for reasons of safety) or organic compounds

such as iodine and zinc. Zinc pyrithione (ZPT) is an

Mystery Solved: The Case of Pink Stain on Vinyl

Left and right—

Developed by a Swiss

sailmaker who is also

active in paragliding,

the In atable Wing

Sail has interesting

attributes such as the

absence of compres-

sion forces.

Below—The IWS is

set on a retractable

“mast.” Electric fans

keep the sail in ated.

Rovings170-ADFinaldig.indd 14 11/2/17 2:57 PM