"DSK" wrote in message
. ..
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!


Doug, Essie takes serious exception to the slanderous allegation that she
was "poorly built." I told her that you really didn't mean it, but I think
it'll be a while before she forgives you.

KLC Lewis wrote:
Doug, Essie takes serious exception to the slanderous allegation that she
was "poorly built." I told her that you really didn't mean it, but I think
it'll be a while before she forgives you.



OK, re-phrase that statement so as not to be pejorative.

However, there is really no reason for a fiberglass boat to
have any measurable flex in it's hull, other than rigidity
(and the strength that is a commensurate by-product) not
being high on the list of builder's priorities. For example,
many years ago a buddy of mine & I went in shares on a fancy
racing boat, a 1-Tonner. Several years past it's prime, of
course, or we would not have been able to afford it.

This boat had been built to be driven *hard* under sail, and
stiffness means speed to a racing boat. The tuning guide
said that at times, it was possible and desirable to place a
tension of 10,000 lbs on the backstay. I spoke to the
builder and asked if the boat would really take this, and he
laughed and said "Heck yes, when we trialed that boat, we
put 20,000 on the backstay and measured a little less than
1/4" deflection along the deck."

In years before and since I've worked on and sailed a number
of boats, and have found some that flex more, some that flex
very little or not at all. Perhaps it's just idle prejudice
on my part, but the ones that flex less seem to me to be
more desirable.

Fresh Breezes- Doug King

"DSK" wrote in message
.. .
KLC Lewis wrote:
Doug, Essie takes serious exception to the slanderous allegation that she
was "poorly built." I told her that you really didn't mean it, but I
think it'll be a while before she forgives you.


OK, re-phrase that statement so as not to be pejorative.

However, there is really no reason for a fiberglass boat to have any
measurable flex in it's hull, other than rigidity (and the strength that
is a commensurate by-product) not being high on the list of builder's
priorities. For example, many years ago a buddy of mine & I went in shares
on a fancy racing boat, a 1-Tonner. Several years past it's prime, of
course, or we would not have been able to afford it.

This boat had been built to be driven *hard* under sail, and stiffness
means speed to a racing boat. The tuning guide said that at times, it was
possible and desirable to place a tension of 10,000 lbs on the backstay. I
spoke to the builder and asked if the boat would really take this, and he
laughed and said "Heck yes, when we trialed that boat, we put 20,000 on
the backstay and measured a little less than 1/4" deflection along the
deck."

In years before and since I've worked on and sailed a number of boats, and
have found some that flex more, some that flex very little or not at all.
Perhaps it's just idle prejudice on my part, but the ones that flex less
seem to me to be more desirable.

Fresh Breezes- Doug King



Well, there's flexing and there's flexing. Essie is built exceptionally
stout for a boat of her size, having been built back in '63 before
scantlings for fiberglass boats had been developed. In those days they
really didn't know how thick things like hulls should be, so they erred on
the side of, "I dunno, Frank. Better lay up another quarter inch or so."

But a boat on the hard is unlikely to be supported the same way as the water
holds her. Essie's cradle supports the keel (full) for a good portion of its
length, then there are two supports foreward and two aft (P&S) -- for a
total of four. Over the length of a winter, with the hull alternately
heating up and cooling off (there are times even in winter when the hull can
be hot to the touch during a particularly bright day, only to drop below 20
degrees f at night), this "support" cannot help but put some unusual
stresses into the boat. When launched again in the spring, it takes a while
for the boat to relax into the water.

Again, with Essie we're talking fractions of fractions, but it's still
noticable. And she is WAY stronger-built than she needs to be. The flexing
we are talking about isn't "oilcanning" from scantlings that push the lower
limit.

KLC Lewis wrote:
Well, there's flexing and there's flexing.

Agreed.


.... Essie is built exceptionally
stout for a boat of her size, having been built back in '63 before
scantlings for fiberglass boats had been developed.

I've heard this a lot, but it's not 100% accurate. The Navy
was very interested in fiberglass for it's small boats
(gigs, whaleboats, utility boats, etc etc, which had been
previously built out of wood). In the early 1950s they paid
for, and published, a large scale engineering study of
fiberglass including how well it stood up to UV. Lots of
early boat builders used this reference.


But a boat on the hard is unlikely to be supported the same way as the water
holds her.

Agreed again. The cradle or jackstands should be positioned
to support the internal structural members, like bulkheads,
directly. And fiberglass will exhibit 'creep' under
consistent heavy load for a long time. But it won't creep if
it's not loaded past the point of measurable deflection.



.... The flexing
we are talking about isn't "oilcanning" from scantlings that push the lower
limit.


Actually, oilcanning is annoying but not particularly bad
for fiberglass. FG can withstand at least an order of
magnitude more cycles of flexing than steel before
fatiguing, in this respect it's far superior to metal.

If given a choice between a hull that had oilcanning in some
panels (for example, the big almost-flat section in the bows
of many boats) and one that flexed over it's whole length
from rig loads, I'd pick oilcanning. But it would be a lot
better to have neither.

Fresh Breezes- Doug King

In article .com,
"Skip Gundlach" wrote:

Once the hull's settled in, I expect that a Loos gauge is the way to
go to see the right setup. I have two questions:

First, is it worth the investment to buy one? I'm not a racer, nor
will I ever be. But I expect that a properly tuned rig will be
kinder to the boat, in any event. Is this something which I'd use
frequently or something better done by paying a rigger (the largest
tool is what our boat needs - it's 180 at list) on the occasions when
I thought I needed it?

Another use you might not have considered: I marked our final settings
on the gauge, and recheck whenever the leeward shrouds look a little
too loose during a hard sail. Takes maybe 5 minutes. Most times, the
static numbers are the same, but one Fall, they were somewhat lower.
Further investigation revealed that our structural bulkhead
(deck-stepped mast) was shifting due to hidden rot. It'd dropped less
than 3/8" and we'd probably have been safe, but Xan got put away early
that year and got a new bulkhead the next Spring.

I do suggest your first setup be checked by a rigger, though. If you got
new sails, your sailmaker might be a good resource. That gives you
independent "eyes" checking your work. I think it's worth the bucks for
the piece of mind.

And shaft alignment DOES change as the boat settles to the new shroud
tensions. Not as much as the initial splash, but enough to cause some
"thunk".

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Replying to my own post again, to concatenate commentary...

Actually, I'm really doing an update and some comments:

First, the Morgan 461 is built like a tank. Even the transom, at the
top, when we cut the hole for the the shower receptacle, was over 3/4"
solid fiberglass. The deck, not counting the 3/4" marine ply core
between the headliner (also molded fiberglass - ~1/8") in most places,
is 1/2" thick solid glass. So, it's hell for stout, and I'm not the
least bit concerned about strength. However, being fiberglass, it
*will* bend, thus the settling time we're allowing.

To the original topic, and some of the chatter about it, sure enough,
the rig is tightening up as we sit. We've been afloat 8 days. From
only one being relatively tight, the shrouds are banjo-tight, and the
lowers no longer wiggle, though they can be moved. I'm presuming
what's happening is that the bow and stern are rising infinitesimally,
bowing the sides out in similarly tiny degree, lengthening the affected
items. However, I've not noted a similar loosening of the backstay -
perhaps that was already overtight..

Coincidentally, while, with the new coupling, I'd not noted a shaft
misalignment, the old (badly mauled!) coupling showed a gap at the top.
If the hull is doing what I surmise above, that would work out that
sort of misalignment, I'd think.

As noted in prior stuff, we're not racers, but ... we do like to get
the most out of our rig. As much as the other refit costs have been,
and with our port supply privilege, having the Loos heavy duty
professional tool aboard is relatively trivial - and now back on my
radar.

As always, thanks for the informed discussion. I was commenting today
to an email acquaintance that my time in this group, doing active
research or learning, is approaching 10 years, predating, even, our
confirmation that we'd do what we're about to set out to do. This and,
now, various mailing lists, have been an invaluable resource, exposing
me to ideas, sources, realities, lectures and the like, leaving me far
better informed than before.

And, while we have yet to pull the plug, I have to confess to having a
bit of enjoyment in reflection on all the potshots taken at us to the
effect that it - even so much as to buy a boat - would never happen.
Each in their own way - mine happens to be one of research and caution
:{))

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery!
Follow us at and



"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails.
Explore.
Dream. Discover." - Mark Twain

In article .com,
"Skip Gundlach" wrote:

I was commenting today to an email acquaintance that my time in this
group, doing active research or learning, is approaching 10 years,
predating, even, our confirmation that we'd do what we're about to
set out to do.

Say it ain't SO! I remember a post from you having recently done a trip
with your now-wife on your ex-father-in-law's boat through, as I recall,
the Bahamas as he pulled the boat home. I find it hard to believe I've
been on the internet that long.....

And, while we have yet to pull the plug, I have to confess to having
a bit of enjoyment in reflection on all the potshots taken at us to
the effect that it - even so much as to buy a boat - would never
happen. Each in their own way - mine happens to be one of research
and caution
:{))

I been pulling for you ;-)

Jealous, too, since I spent a few years in Clearwater and with Momma's
turn of the switch last week up here, I'm seriously considering laying
poor Xan up next weekend for the Winter. I fondly remember comfortably
swimming down there until Christmas.

BTW, if you don't get out before Christmas, expect chilly weather until
about mid-February. I even saw snow once, enough to close down the
interstates in the area -- about an eighth of an inch ;-)


--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/