Page 183 - The Complete Rigger’s Apprentice

fits naturally with all the other gear. If you’re less Galvanic Corrosion
than clear on the nature of the boat, a little study
will help inform your selection decisions. For start- Galvanic corrosion is a side effect of electrical
ers, take a look at the Portfolio of Rigs in Chapter 8. activity. When metals of differing electrical poten-
Rigging involves not only the ability to turn up tial are placed against each other, a little moisture
and warmth is all it takes to form an electrical cur-
a good splice but to do it in the right materials in the rent. The metal with the lower potential is eaten
right size, for the right boat. And to understand why. away by the current.
So if you have, say, a stainless fastener in an
aluminum mast, the aluminum, having the lower
potential, will slowly turn into a white powder over
STAYSAILS time. Fortunately, it’s easy to prevent galvanic cor-
rosion in this situation by isolating the two metals.
For fasteners, a little Tef-Gel or ECK on the fas-
It’s called a staysail because it’s attached to a stay. tener will do. For larger items such as winch bases,
This is ironic, since a staysail is inclined to do any- make a shim out of Mylar or UHMW tape to put
thing but stay. It flaps and flops around when tack- between the fitting and the mast.
Below water, things are tougher, since the water
ing, and is always demanding to be fussed with, conducts electrical current—the pieces don’t even
even when you’ve settled on a course. It takes mus- have to touch, and there’s no way to isolate them.
cling to get it where it needs to go, and even after it’s That’s why boatbuilders strive to minimize dissim-
furled it’s been known to go racing up the stay on its ilar metals below the waterline, and why you put
sacrificial zincs (zincs have low potential, so they
own if caught by a puff of wind. The time-honored get eaten instead of something more expensive)
method of reducing a staysail’s intractability—lash- below the waterline.
ing a boom to its foot so that it becomes self-tack- For the rigger, almost everything is above the
ing—also reduces its efficiency. And that can mean waterline and easy to isolate. The major exceptions
are bobstays, boomkin shrouds, and centerboard
the difference between a daysail and a day-and-a- pendants, which can spend a bit of time under
half sail, or between escaping a lee shore and calling water.
Bobstays are the worst, particularly on heavi-
your insurance agent. ly-laden cruising boats. One way to lessen galvanic
action is to minimize dissimilar metals. So if, for
The Basic Self-Tending Staysail example, you’re working on a wooden boat with
In the quest for sailing efficiency without corre- bronze fasteners, use a bronze rod bobstay.
Another trick is to install a linkplate at the bot-
sponding muscular effort, people have concen- tom end of the bobstay. This gets the stay up out
trated on improved mechanical advantage (read: of the water, leaving the slower-to-dissolve, cheap-
larger, more expensive winches) or easier sail han- er-to-replace linkplate to take the heat.
dling (read: roller-furling/reefing devices). More on
these two approaches later. Right now I’d like to
take another look at self-tending staysails, because
only a self-tending sail can relieve you of sailing’s Skip Green’s
most arduous burden: tacking. And with intelligent Hank Rotation Method
design, loss of efficiency need not be great. Hanks on staysails wear most severely at the
lower end of the sail, and the next most severe
wear is at the top. To prolong hank life, use
extra-large hanks at the top and bottom, and
Headsail Prefeeding switch these two hanks when the wear on the
lower one becomes severe. As an added step, also
With foil-mounted staysails mount two prefeeders switch the second-lowest and second-highest
at the base of the stay, one just below the foil, one hanks; they wear faster than the rest, but not fast
on a short lanyard at the deck. The double prefeed- enough to warrant oversizing.
ers make for much smoother, quicker sail hoisting.

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