How To Remove Bottom Paint From Gelcoat

To Strip? Or Not to Strip?

All things come to an terminate, including bottom pigment.
Hither's how to cope with antifouling separation anxiety.

When she was immature, your boat had a bottom that was as polish as a babe's, with non a dimple or a blemish. Your fingers slid beyond the surface like it was silk. But not anymore: Now her once-flawless gelcoat is hidden past layer upon layer of dead antifouling paint, like rouge on a dowager's cheeks. Your boatyard manager says it'southward fourth dimension to strip her lesser and start fresh. It'll make her slick equally an eel, he says; she'll go faster and burn less fuel. Heck, she'll be like a kid again.

Your checkbook quivers at the idea. Is such a affair really necessary?

"Absolutely not," says yacht designer George Buehler. If the pigment's still sticking, information technology's not flaking off, and information technology's still keeping the critters away, there's no reason to spend difficult-earned dollars and/or elbow grease removing it." Does the weight of thick paint pic and its respective crude surface have whatever real outcome on the performance of a displacement-speed cruiser? "I can't imagine it would be measurable," added Buehler. "Some racers brighten their bottom paint with 600- or 800-dust wet emery textile to shine it to the nth degree, but just the virtually anal of them."

Don't Spare the Sandpaper

All the same, nigh all antifouling paint will somewhen fail. Jeremy Dolan, Technical Service Representative for International Paint LLC, manufacturer of Interlux products (www.yachtpaint.com), said that over many seasons and many repaintings, the accumulated weight of the pigment itself will crusade it to flake off. And once the paint starts to flake, it has to be removed. How can you tell when the pigment's getting too thick? "If there's an bodily ledge against the masking tape at the waterline, it's time to at least sand it to take some layers off," he said.

Dolan explained that an energetic set on with 60-grit paper can coax more than years from your bottom, and let you schedule the consummate task on your own terms—peradventure you don't have the budget for information technology this year, or the job will filibuster launching your boat, and you'd rather exercise it next spring. And yous might make a improve deal with the boatyard if yous piece of work with them on scheduling: Glen Billings, proprietor of Billings Media Blasting (www.billingsblasting.com) in Glastonbury, Connecticut, works for boatyards throughout New England. He said that yards usually adopt the bottoms stripped in the fall, then they tin can prep and recoat as weather condition permits over the winter, when work is scarce. Gunkhole owners tend to wait until spring, when everybody's decorated.

Note that every paint manufacturer recommends sanding before recoating to remove some of the dead paint and better adhesion of the new glaze. It'due south a directive that's overlooked every bit oft as it is followed, merely it will earn you more years out of your bottom. Boatyards don't like sanding considering it takes time, and lesser painting is priced per foot, not per hour; sanding isn't rough simply on paint, but on profits, besides. And the paint sticks fine without sanding—until it doesn't. Today, about yards insist on doing all hull work, for environmental, liability, and economic reasons, simply if you tin find a chiliad that lets you practice your own work, use your own free labor to prep your bottom properly. Then pay the yard to paint it; they have to make a living, too.

How To Strip Your Bottom

There's no secret about the all-time way to strip your bottom: Use your checkbook. For all simply the smallest boats, information technology's a job best left to professionals with the necessary equipment and expertise to go the task done quickly, thoroughly, and without hassles. The final matter you demand is the guy next to you in the thousand calling the Green Law because you didn't dispose of stripped pigment in an environmentally correct manner. (The stuff is toxic, after all.)

If you insist on doing a strip job yourself, your options are mechanical (scraping and sanding) or chemic, using a liquid stripper similar Interlux Interstrip 299E, Soy Strip (www.franmar.com), or a paste/paper product like Peel Abroad Marine Strip (dumondchemicals.com). Dry out scraping is torture, chemical stripping is messy, and if you have many layers of paint on the bottom you'll probably take to apply peel products a few times.

Whichever method yous cull, wear centre protection, and a pro-quality combination respirator that filters both dust and fumes—don't rely on a cheap paper mask. Once the pigment is off, y'all'll be using solvents to clean and prep the lesser, and you lot'll capeesh the respirator.

For my coin, blasting is the fastest, most efficient, and most economical way to remove antifouling paint. A pro like Billings can strip your boat in a twenty-four hours. He uses crushed walnut shells to remove the soft antifouling without damaging the harder gelcoat or barrier coat underneath. The walnut shells will sometimes open blisters, just if boat pox is an event, Billings volition utilise sand instead to open them upwardly. When the blasting is done, there should exist merely a tinge of color left on the hull, he said, the effect of the beginning coat of antifouling being "done properly"—laid over primed gelcoat or a tacky bulwark coat to form a potent chemical bail. If yous end up with nice clean gelcoat, the pigment wasn't practical correctly in the get-go place.

Some professionals "dry blast" with but air pressure as a propellant, while others "slurry blast" with water to keep the dust down. Billings prefers dry blasting because it makes clean-up easier: He tents the lesser to corral the dust and spent annoying, and lays down plastic sheets under the gunkhole to take hold of the droppings; when the chore is done, he simply rolls up the plastic and disposes of it. With moisture blasting you accept to incorporate the water, as well, he said. "Yous can't keep things make clean enough." (Proponents of wet diggings say well-nigh of the water evaporates away, and at worst you get muddy debris.) Bottom line is, it'south the blaster'southward selection: As far as the job is concerned, both methods become 'er done.

While you don't have to become a blaster and strip your own lesser, learning a bit most information technology tin can help you detect the correct expert, or the right chiliad, to do the chore. MMLJ Manufacturing has been building sandblasting equipment since 1941; their Dustless Diggings (www.dustlessblasting.com) process uses water and recycled crushed drinking glass to strip the surface. A visit to their website volition give yous a quick didactics in diggings.

Visitor spokesman Ryan Detablan said MMLJ will sell you lot a standalone dustless equalizer if you're serious about doing your own lesser stripping. Model DB800 is but right for virtually applications. It comes with the compressor, blaster, h2o tank, and all associated gear mounted on a trailer; just hook it up to your truck and drive away. Toll is almost $49,500, though, so maybe you'd rather just rent a pro. On the other mitt, there are a lot of bottoms out at that place overdue for stripping.

This article originally appeared in the April 2015 issue of Power & Motoryacht magazine.