They’re Back and They’re Worse Than Ever!

[Russ]

What To Do About Polyestermites?

Many years ago the entire boating industry and every boater learned about a then-new problem with fiberglass boats, namely osmotic blisters. A walk through a boatyard will reveal that the problem is still with us, but boatyards have learned to deal with this expensive problem. At last, a cure was found, and boat builders have developed resins and application methods that have substantially, although not completely, eliminated the problem in new boats.

And then several years ago the Environmental Protection Agency alerted boaters to a new and equally expensive problem with the gelcoat on fiberglass boats. Like the Zebra Mussels that first invaded the Great Lakes and killed off oysters and clams and completely fouled water intakes on boats, we were alerted to the problem of polyestermites. They were first noted in the Bahamas, and then a few were detected in Florida. It was assumed that they were transported to Florida by boats spending the winter in the Bahamas and then returning to Florida in the spring.

Now marine experts are reporting a resurgence of this damaging parasite. Like the Zebra Mussels, they are not native to U.S. waters, but with today’s mobile society, critters in one part of the world are easily transported to another. If the environment is hostile the transported species soon die off. The EPA has been tracking the spread of Zebra Mussels for the past several years to see just how far the infestation will spread. There is not much they can do about them at this time, but ocean scientists are still searching for a method to control them.

Nothing has been written in the boating press at this point about Polyestermites. However, this spring their infestation was noted as far north as Rhode Island. Scientists had thought that Polyestermites could not survive in the colder northern waters, but the US Department of Environmental Protection has now issued an alert for boaters. An obscure article in the Federal Register has not received much attention by the press, but you can be certain that the pages of our boating magazines will soon carry large, bold headlines about this resurgent problem for boaters.

So what the heck are Polyestermites, and what is the problem? They are small barnacle-size snaillike creatures that attach themselves to the bottoms of boats, pilings, and bulkheads. They seem to have an affinity for boats, however, because most are now made of fiberglass. Other than their slimy appearance, they do no damage to pilings and bulkheads. Fiberglass boats, however, are another matter. Polyestermites are not deterred by anti-fouling paints, and, in fact, they seem to thrive on them. They eat their way through bottom paint, and then have gelcoat for dessert. They seem to secrete a substance that dissolves gelcoat into a paste that is then consumed. What is left are areas about the size of a dime where the gelcoat is completely gone leaving the fiberglass and resin exposed to salt water. Interestingly, Polyestermites cannot survive in fresh water, but most of us operate our boats in salt water.

Once the gelcoat is consumed and the fiberglass and resin are exposed to the water, the water begins to degrade the fiberglass resulting in expensive repair. Repair is similar to that for osmotic blisters. The gelcoat has to be taken down to the fiberglass, and several coats of special resin that these pests seem to abhor has to be applied, and the bottom then painted with anti-fouling paint. Whereas the anti-fouling paint itself still will be attacked by Polyestermites, they cannot penetrate into the fiberglass. And since most of us haul our boats during winter, other than pockmarks in the paint, no further damage is done.

The Federal EPA is preparing a twenty-page booklet fully explaining Polyestermites, and the procedure for their detection and repair of their damage. It also discusses preventive measures we can take to prevent their damage.

Whereas the US is just now being invaded by Polyestermites, it is something with which we boaters will have to deal. The EPA says this booklet will be placed on its web site, but that probably will not occur until this summer. In the meantime, we can obtain copies from the EPA in Washington.

[Maraquita]

I already got my booklet, Russ and am preparing to apply the preventative paint even though I only sail in Rocky Mountain lakes. Can't be to careful with something this dangerous!

[Russ]

I already got my booklet, Russ and am preparing to apply the preventative paint even though I only sail in Rocky Mountain lakes. Can't be to careful with something this dangerous!

Good on you. Same here. I'm going to apply that coating just in case they make it into our waterways.

[NiceAft]

Russ,

You don't mention anything about a barrier coat.Is there anything about a barrier coat offering better resistance?

[Russ]

Russ,

You don't mention anything about a barrier coat.Is there anything about a barrier coat offering better resistance?

Sorry Ray, you will have to look at the date of the original post for the answer.

[dlandersson]

Thank you

Interestingly, Polyestermites cannot survive in fresh water, but most of us operate our boats in salt water.

[NiceAft]

Russ,

You don't mention anything about a barrier coat.Is there anything about a barrier coat offering better resistance?

Sorry Ray, you will have to look at the date of the original post for the answer.

APRIL 1st……….You got me….HOOK, LINE….AND SINKER.

[OverEasy]

So Russ…..
Where do you want that 50 feet of 3/8” braided shoreline you ordered delivered?

[Russ]

So Russ…..
Where do you want that 50 feet of 3/8” braided shoreline you ordered delivered?

shoreline?

[kmclemore]

Well played, Russ!

[OverEasy]

Also did you ever find the left handed smoke shifter?

I’m still searching for a good skyhook if you happen to come across one