Submitted on April 5, 2007 by Tom Berkemeyer

Question: I sail in the tropics and have had serious mold problems with two different laminated sail cloth products. I want the shape and performance that a laminated sail provides but I don't want grey sails that break down in 3-4 years as the mold destroys the bonding agent in the laminated cloth. Any ideas?

Thanks,
Tom on Guam

Answer: Dear Tom on Guam:

Mildew growth on sails is an ugly problem for sure – particularly with laminated sailcloth featuring mylar films. North Cloth cruising cloth styles incorporate fungicide right into the laminating adhesives to help battle mildew. The battle should continue onboard by making sure wet sails are dried at the first opportunity (ideally rinsed with fresh water before drying). Storing a wet sail in a warm dark space - like most sail storage lockers for example – inevitably promotes mildew growth. Likewise, a sail tightly furled with UV protection acts as a good mildew incubator. Even if a sail is dry when furled up, pollen-laden rainwater finds its way down into the roll and promotes mildew growth.

There is some good news. The first is North Cloth continues to work on the problem in conjunction with emerging technologies in the biochemical field. There is a widespread global focus on this problem because of ever increasing use of “high tech” laminated and/or “plastic” materials in construction, apparel, packaging, etc. Progress in the battle against mildew can be expected,

The second bit of good news is that mildew in sailcloth is effectively a cosmetic problem. We monitor, measure and record the adhesive bond of all our laminates – during lamination, and as a final QC test before putting cloth rolls on our shelf. We have exhaustively tested the lamination bond in well used, mildewed cloth to determine whether mildew causes any significant change in bond quality. The simple answer is that it does not. Stories about delamination or other failure in cloth caused by mildew are misguided or incomplete. I suspect botched attempts to remove mildew using inappropriate cleaning solutions for the type of cloth being treated may add to the confusion. Not surprisingly, this is a good argument for working with the most experienced and best equipped service loft when having your sails repaired or tidied up.

Regards,

Tom Davis
North Cloth

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