centerboards . . .

[hokeyhydro]

Much discussion over centerboard foiling and the like, but query is traction related. I believe standing on the centerboard is SOP for righting a capsized dingy. I plan to coat my board with graphite/epoxy mix mainly because it looks cool and if the boat goes a smidgen faster that would be neat, but graphite is slippery and I imagine trying to stand on a slippery board would be an adventure. Will I need a traction strip? Shoes with tree-frog suction feeties?

[Chick Ludwig]

In practice, it doesn't seem to be a problem, unless the graphite makes it so. Back in my outboard racing days, we tried all sorts of stuff like graphite on our hull bottoms. Never could tell a difference. some studies showed that a clean, smooth bottom freshly washed with detergent worked as well or better than anything. Interestingly,one of the worse things to do was to wax it.

[hokeyhydro]

Yeah, wax bad on a race boat bottom. The hydros I designed and built had so much air under them the bottom finish didn't matter, but I did do graphite on one for "gamesmanship" AKA pit scare points. While the boat was upside down and wet after racing I sat on the bottom, which was sort of angled down, and slid right off! Spilled my dang beer - drats. So I do wonder about attempting to stand on a slick CB . . . might be touchy.

[Dale Niemann]

Stand on a slick CB.  Now that is a excellent thought.  How might that happen?

dale

[Chick Ludwig]

Yeah, Hokey--I remember the "gamemanship" ---Messing with there minds as we would say today. i put a pressure regulator on my B-stock once. It didn't do anything, but the next race, almost everyone else had one!

[PAR]

In practice, you grab the centerboard and pull it down. At this point the boat is less then 90 degrees to vertical and you put a knee on the board while you grab the rail, sheet or whatever is handy. The boat continues to roll upright and if you time things right, you can climb in as she comes up. This assumes you've released the sheets, unfouled anything that might hamper the booms movement, swung the bow into the wind, etc.

 

Graphite does make a board smooth and hard, but slick isn't what I'd call it. Speed improvements will be measured in fractions of a 1/10th of a knot, so not as worthwhile in this regard as it might seem. Its real benefit is slipperiness within the case, so it's easy to lower and raise. I guess what I'm saying is, if you practice capsize recovery a few times, you'll get a feel for the sequence of events and not be surprised by things, when it does happen unexpectedly. With some practice, you'll recover from a capsize in a minute or less, much of it will be moving with the boat, as it tries to right itself, with your help. Done well, you and the boat will find each other in the same place, just as she rolls back to her bottom. You'll be in a wet heap on the cockpit sole or seat and she'll be upright partly swamped and pissed you weren't faster with the sheets a few minutes earlier.

[hokeyhydro]

Thanks, PAR. Your description of the capsize rescue tells me I won't be standing on the board, which is the way I imagined it to be. Yes, zero experience with centerboard boats. The catamaran I built for my daughter is rather easy to right, but then it has never turtled = wood mast helps there.

[ecgossett]

I wet sanded most of my graphic epoxy bottom, I didn't have time to finish it all. You can feel the difference, between final coats, and then the 180 and wet sanding.

[Garry]

I used to capsize my 15' Sidewinder often enough that I developed a routine that worked sometimes. I enjoyed sailing on the edge single-handing in heavy winds. When the boat was committed to the capsize, I climbed over the up side and stood on the centerboard, rocked the boat back upright and climbed back in. Hardly got my feet wet.

 

Most of the time, though, it was as PAR describes. Swim around to the centerboard and pull down on it by hand.

 

One thought - If the graphite is not to reduce water resistance but really to reduce resistance in the centerboard case, put the graphite on the inside surface of the centerboard case only. One advantage is easier repair of the centerboard when dinged without having to deal with the graphite.

[PAR]

I prefer to use Teflon or HDPE sheets inside the case, instead of the bother of graphite on the board or case. It's self lubricating, tough and can be easily replaced if necessary. A notched trowel with some polyurethane or epoxy will hold it well enough.

[Tom Lathrop]

One thought - If the graphite is not to reduce water resistance but really to reduce resistance in the centerboard case, put the graphite on the inside surface of the centerboard case only. One advantage is easier repair of the centerboard when dinged without having to deal with the graphite.

After trying most of solutions that people use to hold a daggerboard in place on a racing sailboat, I finally worked out something infinitely better.  I glued strips of felt along the inside bottom of the DB trunk.  Thickness is adjusted to allow movement and hold the DB wherever it is positioned.  A giant plus is that the DB can be adjusted on any point of sail, even loaded to windward.  No moving parts, its always there ready to work.   Most fiberglass boats have wider slots that might need a thicker material like carpet to achieve the same result. 

 

Incidentally, no surface coating has ever been proven to reduce skin friction.