Bottom Paint Out of Water
I have read several of your test comparisons of bottom paints and found them useful. However, there is one point that was not mentioned. The repair yard that I use has told me that once bottom paint has been submerged, it absorbs water. If the boat is later hauled out and the paint dries out for more than 36 hours, the paint will lose its effectiveness at reducing marine growth.
Can you tell me if this is true and if it applies to all brands of bottom paint? I don’t think the yard was just trying to sell me a new bottom job. The boat was hauled for a different problem, and the paint was only about a month old.
Your yard wasnt BS-ing you, but a given paint’s ability to retain its antifouling effectiveness out of water depends on its type.
Popular antifouling paints generally fall into the following categories: ablative, epoxy, and vinyl. There are other special types, such as Teflon-based paints that contain no biocide and old-fashioned sloughing paints that arent used much anymore. Boats with soft sloughing paints generally must be launched within about 48 hours.
Modified epoxy paints such as Pettit Trinidad and Interlux Ultra contain the highest amounts of cuprous oxide biocide and are most resistant to abrasion. On the downside, they are not particularly easy to sand. Out of the water, they gradually lose their effectiveness. Interlux says, “Hard antifouling paints work by leaching biocide out of the paint film and leaving the paint film behind. When this paint film is left out of the water it oxidizes and any biocide that is left in the coating will not leach out at the proper rate to control fouling.”
Sixty days is about max to leave them dry, though in our tests Pettit Trinidad rated as well as the best ablative paints over several seasons, during which time the test panels were dried out over winter. The surfaces were “reactivated” by brushing lightly with a scrubby pad.
New copolymer ablative paints do not lose their antifouling ability in the presence of air, so can be left out of water during a haulout or over the winter. Interlux says its multi-season Micron Extra and Micron CSC copolymers “retain their antifouling properties as long as the paint is on the hull.”
Fiberglass Bottomkote, however, is just a single-season ablative paint and begins to lose its effectiveness when out of the water for more than about 30 days.
Ablative paints are soft and scrubbing can cause a considerable loss of coating. Interlux likens them to a bar of soap wearing away. The upside of this quality is that ablative paints don’t tend to build up as much as other types and so require less work preparing the surface before repainting.
Vinyl paints are used almost exclusively by racers because the boat’s bottom can be burnished and made more smooth than with other paint types. They shouldn’t be left out of water more than about 30 days either. And, vinyl paints have serious compatibility problems with other paint types, so before applying one you usually must sand the bottom down to bare gelcoat. A vinyl paint applied on top of, say, an ablative paint, will cause the undercoat to lift.
Bottom line, Don, is if your paint-modified epoxy or copolymer ablative-is only a month old, it’ll probably continue to perform fine. If it’s a hard paint, scrub it lightly before relaunching.
I have an Aquarius 23, a trailerable sloop manufactured by CoastalRecreation, Inc (now defunct) in the early 1970s. There are four windows for the cabin made of some type of plastic material (Plexiglas or Lexan?) which is now showing its age. A “crazing” pattern of cracks is appearing around the edges of the window, although this seems mostly cosmetic, because one cannot feel any irregularity on either side of the pane. I fear that someday the windows may collapse.
Do you know of any product which can correct this aging defect?
-Rabe F. Marsh
It sounds as if you have Plexiglas (acrylic) windows (they would probably not be Lexan). After 30 years they’ve started to succumb to UV degradation, cracking due to many thermal changes, and plain old age. They probably won’t simply fall apart, but don’t expect them to stand up to a lot of pounding or pressure.
We’re assuming that these windows are flat, not formed to a complex shape. The best idea would be to remove them while they can still be used as templates, and take them to your local glass store. They should be able to cut you new ports of heavy-duty acrylic at a reasonable cost.
Technical advisors at Atofina, makers of Plexiglas, recommend specifying a cast acrylic to withstand chemical attack better.
I read with interest the article on in-boom furling in the Oct. 1 issue. Just before rushing out to order one I remembered that on my 1960 Rhodes 41 I could turn my wooden boom and the sail would roll on to it like a window shade. Once it was all rolled up I could protect it with a relatively inexpensive cover that goes on in minutes. This ain’t rocket science and it’s 40 years old. What am I overlooking here?
Actually, a modern version of the old crank-powered roller-reefing system wouldn’t be a bad idea, as long as the sparmakers could fabricate geared gooseneck fittings strong enough to work day in and day out. However, that rig does presuppose several things: 1) that your boat has end-boom sheeting, or can be retrofitted with it successfully. 2) that you have full-length battens, or that your existing short batten pockets are aligned exactly parallel to the boom, so that the 3 or 4 battens in your main will roll up neatly. (As you know, on most mainsails, short batten pockets are sewn in parallel to the sails panels, not to the boom) 3) -and this is the biggie-that you’re willing to give up your vang any time the sail is rolled up even a fraction. In any case you’d be limited to a removable rope vang, not a solid one. 4) with or without the vang, you’ll need an adjustable topping lift to hold the butt of the boom at the proper angle.
Having been a long-time subscriber and pack rat I looked through my years of old Practical Sailors for information on putting out a “winter stick” on my mooring in the New Meadows River. I also checked Chapman Piloting and the Annapolis Book of Seamanship. Nothing!
I have 10 feet at low tide, with a tidal range of approximately 9 feet. We get a considerable amount of ice in the river and current runs of 2-3 knots at mid-tide. Can you help? When to use? How to build? Sources of information? Thank you for your help. It’s getting cold up here already.
-David G. Williamson
W. Bath, ME
For those lucky enough to live in places where they can sail year-round, the term “winter stick” may be obscure, just as “colada” is to us.
The purpose of the winter stick is threefold: 1. It keeps your regular mooring ball from getting mangled and breaking off in the ice, thus losing your mooring for you (or at least hiding it until you can grapple or dive for it in the spring) 2. It protects your mooring chain by dropping it down into the protective mud or sand for the winter. 3. It provides, or should provide, visible markers in the mooring field for boats underway in the winter. This is one of the worst things about winter sticks-poorly made ones tend to lie flat or even submerge until they’re barely awash, and end up as hazards to anyone passing through.
You can make a winter stick in several ways. A friend of ours makes them out of 4″ PVC tubes, capped, with weights in the bottom and day-glo orange paint at the top. We used to make them out of 2×4 pine, painted with white or yellow topside paint to keep the water out, with a perforated brick lashed to the bottom and a hole drilled for the line.
There’s really no such thing as a “standard” winter stick-most are cobbled-up affairs that we all make in a hurry when the weather changes and our hands get too cold to allow us to be persnickety.
However you build the stick, make sure it floats more or less vertically and visibly. This may take a little experimentation with weights at the bottom. If it seems to sink too low, you can always attach some foam flotation at the mid-point.
You have a lot of tide there-you’ll need to make sure to use enough line so that at high water the whole thing won’t be submerged. It sounds as if 30-35 feet of line should do the trick.
Pull as much of your chain rode as you can out of the water, so that you’re close to being right over your mushroom anchor. Mark that spot with your GPS. Can’t be too careful-ice can take a winter stick with it, too, although they seem to survive remarkable well, even in heavy ice.
Then pull your chain back out as far as you can-downwind from the prevailing breeze is best. Take off your regular mooring ball (being careful to belay the chain to something solid in case you lose your grip on it when taking the ball off).
Tie one end of your winter stick line to the end of the chain or swivel. Use a bowline with a good tail and an extra hitch. Tie the other end to your winter stick. Drop the assembly overboard, brush the baby shrimp and other crawly things off your pants, sluice down the decks, and proceed ashore to thaw out your hands. This is best done with a hot-buttered rum between them. Have a good winter.