November 30, 2010

Don’t let blisters bug you

“SHOULD I BUY a boat with blisters?” That’s the query from a reader in San Diego. “Cautious” has fallen in love with a 10-year old, 30-foot sloop, but he’s scared to tie the knot. He’s afraid to commit, because when he had her surveyed he found she had “a whole lot of dime-sized blisters on her bottom.”

Well “Cautious,” my advice is to grit your teeth and buy her. Nobody’s perfect, and no boat is, either. Although fiberglass boats have been around for more than 50 years, there’s still a lot of misinformation doing the rounds, especially regarding the dreaded boat pox.

It’s reassuring, therefore, to hear the experience of David Pascoe, a marine surveyor based in Destin, Fla., who says that in 30 years of surveying and examining 4,000 hulls, he has seen fewer than 10 cases where blisters have resulted in serious structural degradation of a hull.[1]

We’re talking here of dime-sized blisters. In 99 percent of the boats Pascoe has surveyed, blistering involved only the gel coat and the surface mat — neither of which is a structural part of the hull laminate.

Pascoe says that even boats with numerous blisters up to about 1-inch in diameter usually show no significant weakening of the plastic. As a result, “moderate blistering on an older boat rarely impedes the sale.”

As a matter of fact, Pascoe reckons that by the time a boat is 8 or 10 years old, “whatever is going to happen to the hull has probably already happened.” That means if she hasn’t developed blisters yet, she’s not ever likely to, so don’t be tempted to apply a barrier coat.

It’s quite another matter if a new boat develops blisters, of course. On a boat that’s been afloat for only two or three years, it’s likely that blistering is just the beginning. That’s not good news. But one that’s been afloat for eight years or more without developing blisters is a pretty safe bet.

Interestingly, Pascoe doesn’t even think it’s necessary to do anything about small blisters. Admittedly, they make the hull more difficult to paint and they will slow the boat down slightly, but: “If blisters cannot be shown to be causing significant damage, then repair is certainly not mandatory, despite the many horror stories you may hear from people trying to sell you a costly repair job ... Bear in mind that blister repair jobs are now big business for boat yards, so that taking advice from yard managers may not be a good idea.”

He makes another good point, too: “Further, you should be aware that the number of failed blister repair jobs that surveyors find is very high. No one’s ever going to know why blister repairs fail because no one is going to spend the money to find out.”

So go ahead, “Cautious.” Be brave. Put your money where your heart is. Who else is going to see your new girl-friend’s bottom anyhow?


Today’s Thought
The desire of perfection is the worst disease that ever afflicted the human mind.
— Fontanes, Address to Napoleon, in behalf of the French Senate, 1804

Boaters’ Rules of Thumb, #127
Locating faint lights. To find a faint light, such as a star, at night, look a little to one side, or above or below where you might expect to find it. If you look straight at an object, the light rays fall on an area inside the eye that is not as sensitive as the surrounding areas. So faint lights are often first seen in or toward the corner of the eye.

”Why do you call it love at second sight?”
“I didn’t know she was rich when I first saw her.”

1 comment:

Aaron Headly said...

Also: even if fixing blisters is largely an aesthetic exercise, it is a pretty straight-forward sort of job. Most people considering old-boat ownership will probably be competent to do it themselves (assuming the blisters bother them enough).

I'm pretty certain that rehabbing an ugly duckling fiberglass boat is a lot cheaper than building one from scratch, and can offer a considerable amount of the same pride of accomplishment.

It's even 'green', isn't it? Now that I think about it, I realize that I've probably put more physical effort into sorting glass, plastic and cardboard for recycling in the past year than I have put into my 30-year-old boat.