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DSK DSK is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 1,419
Default Sailing fast and Loos

Skip Gundlach wrote:
Of the several power folks I've spoken with, there was unanimity that I
should wait (varying from a week to a month, with a couple of weeks
being a consensus of adequacy) for the hull to stabilize before trying
to realign the propshaft.


I guess more boats are more poorly built than I realize.
Most of the boats I have experience with, including our 22yo
36' Taiwan-built trawler, have very little or no deflection
when set up on jackstands, and no need whatever to
"settle." In a boat that has more than a tiny fraction of an
inch deflection, I'd think they need some structure re-tabbing.

Fiberglass is wonderful structural material, and most of the
people designing boats know how to spec a girder or panel.
Must be the builders!



-----

Lots of great info there, and likewise very helpful links. Thanks so
much to all for those.


You're very welcome. Most of what I wrote was cribbed from
earlier posts I wrote to answer similar questions.

.... Given the purely cruising nature of our boat,
we don't have adjusters nor running backs - though, given the added
inner forestay, it might have been a good idea. So, the rig will
remain tensioned and static, other than the occasional times we might
pull the inner off to the side (removable fitting), which I presume
would change the shape of the mast slightly.


If you're going to fly a sail from that inner stay, you'll
want to set it up pretty tight, and of course it should be
opposed by increased tension on the aft lowers.

Remember, anything less than 10% of the wire's working load
will let the wire stretch, and will not pre-load the toggles
& pins... you will then have shock loading on the rig and
that can produce rather bad results.


One minor question, which seems counter-intuitive to me: Pulling the
lowers to as to bow the mast AFT. Why is that? If any curve, I would
think it should be forward...


You're right. I was assuming that either your spreaders rake
aft, thus inducing bend in the mast, or that you have double
lowers.

Coincidentally, I was talking yesterday with one of the yard guys who
previously was the head rigger at Catalina.

He essentially echoed the above comments about alignment, but said that
once snug and firm, a couple of full turns on each of the turnbuckles
would be about right.


That could produce either dangerous under tension or a rig
that gets progressively out of column under more loads....
bad advice IMHO. Maybe he's the reason why Catalinas are not
Baltics




As we sailed it over, in mostly very heavy weather, it balanced very
nicely, so I presume the rake is about right. Until we played with it
in nearly 30k, pinching tighter and tighter, making it heel
substantially, we had no weather helm nor lee helm we could discern.

So, I'm pretty comfortable about the angle of the mast.


Sounds good, although you might want to add a little bit of
rake. Some weather helm is good. I would recommend taking a
tape measure to the main halyard and measuring the rake in
some way that is clear & repeatable, and writing this in
your maintenance log. That way you don't have to start from
scratch if you ever take the mast down.



Once we get to sailing, we'll check out the lee cables. If they are
slack under any but very substantial loads, we'll take up some more on
the tension, duplicating the turns on each side, but still checking for
straight line in column.


Right. Get the boat heeling about 20 degrees and the shrouds
on the lee side should not be noticably slack... the tension
will definitely drop, but they shouldn't be slatting around!

One funny thing I have noticed, many boats do not have the
same tension on opposite shrouds when the mast is set up
straight & proper. Can't explain it, but it's that way on at
least a dozen boats I've played at tuning up. Oh well, if it
was an exact science, it wouldn't be fun.

Fresh Breezes- Doug King