Mast Wedges
 

When we bought the boat there were only a few wedges in place, not enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite after
it sets?, does it allow some movement or does it harden as a solid rubber?

Bill, http://www.billangiep2.blinkz.com/

BillP wrote:
When we bought the boat there were only a few wedges in place, not enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite after
it sets?, does it allow some movement or does it harden as a solid rubber?

Bill, http://www.billangiep2.blinkz.com/

One of the guys in my YC seals the mast opening with a piece of line
jammed into place (ater adjusting the stays to give him proper rake),
then coats it with silicone. Since we have to drop the mast every year
for haulout, it seems to work well for him

"BillP" wrote in message
lkaboutboats.com...
When we bought the boat there were only a few wedges in place, not enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite after
it sets?, does it allow some movement or does it harden as a solid rubber?

Bill, http://www.billangiep2.blinkz.com/


Filling the are with silicon probably would provide a good job since
the silicon wouln't necessarily fill the entire area.

Spartite is great stuff. Yhere are two varieties. One is pretty firm, the
other is less so. I have the form one. It has been in place for 5 years
now with no leaks or problems

Doug
s/v CAllista

"WaIIy" wrote in message
...
On Sat, 15 Jan 2005 14:47:58 GMT, "Jim," wrote:

BillP wrote:
When we bought the boat there were only a few wedges in place, not
enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite
after
it sets?, does it allow some movement or does it harden as a solid
rubber?

Bill, http://www.billangiep2.blinkz.com/

One of the guys in my YC seals the mast opening with a piece of line
jammed into place (ater adjusting the stays to give him proper rake),
then coats it with silicone. Since we have to drop the mast every year
for haulout, it seems to work well for him

Which brings me to a question. I know next to nothing about sailboats
and I notice in a marina near me (Cleveland) that some of the sailboats
take down the mast for winter and some don't.

There seems to be no pattern to this as their are saiboats from 20 ft to
40ft +.

Is there a particular reason to take the mast down?

It is strange. Some marinas require that you take the mast down when the
boat
is on the hard, some don't. Where I live (Baltimore/Annapolis area), I know
of no marina that requires it. I am in a boat related business and visit
dozens of marinas. None have any policy regarding masts during storage.
I have heard that marinas further north sometimes have such a policy,
but in the Watertown, NY area up into Kingston, ONT I came across
dozens of marinas with boats on the hard with masts up. I can think
of no substantive reason to require masts be unstepped during storage.
Perhaps in hurricane prone areas to the south it may be a good idea.
We have gone through 2 hurricanes up here in the last 5 years with no
boats toppled. In fairness, the winds didn't get much above 60 MPH.
We stayed in the water for both with no damage. The marina was more
concerned about the stands beong eroded due to runoff rather than
wind load on masts.

Doug
s/v Callista

OOPS! I misstyped. What I mean't to say was:

"Filling the area with silicon probably would NOT provide a good job since
the silicon wouln't necessarily fill the entire area."

Actually, I doubt if sillicon would be stiff wough to provide proper support
anyway.

Sorry,
DOug

"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
"BillP" wrote in message
lkaboutboats.com...
When we bought the boat there were only a few wedges in place, not
enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite after
it sets?, does it allow some movement or does it harden as a solid
rubber?

Bill, http://www.billangiep2.blinkz.com/


Filling the are with silicon probably would provide a good job since
the silicon wouln't necessarily fill the entire area.

Spartite is great stuff. Yhere are two varieties. One is pretty firm, the
other is less so. I have the form one. It has been in place for 5 years
now with no leaks or problems

Doug
s/v CAllista

WaIIy wrote:
On Sat, 15 Jan 2005 14:47:58 GMT, "Jim," wrote:


BillP wrote:

When we bought the boat there were only a few wedges in place, not enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite after
it sets?, does it allow some movement or does it harden as a solid rubber?

Bill, http://www.billangiep2.blinkz.com/


One of the guys in my YC seals the mast opening with a piece of line
jammed into place (ater adjusting the stays to give him proper rake),
then coats it with silicone. Since we have to drop the mast every year
for haulout, it seems to work well for him


Which brings me to a question. I know next to nothing about sailboats
and I notice in a marina near me (Cleveland) that some of the sailboats
take down the mast for winter and some don't.

There seems to be no pattern to this as their are saiboats from 20 ft to
40ft +.

Is there a particular reason to take the mast down?
In our case it's because we haul with a crane, and nobody wants their
mast to tangle with the crane boom.

"BillP" wrote in message
lkaboutboats.com...
When we bought the boat there were only a few wedges in place, not
enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite after
it sets?, does it allow some movement or does it harden as a solid rubber?

Bill, http://www.billangiep2.blinkz.com/

Bill,
I used a system that I had seen on small racing keelboats - have a look at a
J-24.

I made a template of the deck opening and of the mast profile.

I put the mast in place and adjusted the rigging (but not too tight) so as
to position the mast with proper rake. I then measured just where the mast
was with respect to the deck opening.

I then made a plug for the mast opening by laminating some plywood - I
included a larger flange on the top so the finished unit would not fall
through. I then cut an opening in the plug for the mast (using bandsaw). I
made the plug and the mast opening slightly oversize so that the mast could
move a bit - no need to have it too tight. Then sawed the plug in half - Put
aft section in first - step mast then push in forward half.

Cost is nominal - just some plywood & glue plus a coat of varnish and mast
always goes back in same position.

On 16 Jan 2005 12:04:04 -0600, Dave wrote:

On Sat, 15 Jan 2005 15:29:11 GMT, WaIIy said:

Is there a particular reason to take the mast down?

Sure. The marina gets to charge you for it. So if they can get away with
requiring it it's more dollars in their pockets.

Reminds me of a situation on City Island. A few years ago the State EPA came
through and fined all the marinas who were letting owners paint their own
boat bottoms, claiming it violated rules relating to pesticides. So the
marinas started to require the work to be done by the marina. EPA later
acknowledged that its interpretation of the law had been wrong, but the
marinas found the rule profitable and have kept it in effect.

My winter storage yard will do it any way I want. I always have the
mast stored inside because I don't fancy moisture freezing in the
Navtec termination fittings.

I have had to replace swaged 1x19 shrouds on other boats half the age
of Gjoa.



Rodney Myrvaagnes NYC J36 Gjo/a


Capsizing under chute, and having the chute rise and fill without tangling, all while Mark and Sally are still behind you

"WaIIy" wrote in message
...
On Sat, 15 Jan 2005 14:47:58 GMT, "Jim," wrote:

BillP wrote:
When we bought the boat there were only a few wedges in place, not
enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite
after
it sets?, does it allow some movement or does it harden as a solid
rubber?

Bill, http://www.billangiep2.blinkz.com/

One of the guys in my YC seals the mast opening with a piece of line
jammed into place (ater adjusting the stays to give him proper rake),
then coats it with silicone. Since we have to drop the mast every year
for haulout, it seems to work well for him

Which brings me to a question. I know next to nothing about sailboats
and I notice in a marina near me (Cleveland) that some of the sailboats
take down the mast for winter and some don't.

There seems to be no pattern to this as their are saiboats from 20 ft to
40ft +.

Is there a particular reason to take the mast down?

I suppose a marina might require this depending on the lifting equipment
they have and also the type of cradles that are commonly used. A lot of
yacht clubs do not have travel-lifts and consequently must use cranes to
remove member boats in areas where it freezes over. As pointed out, its
likely to be impossible to use a crane and sling while the mast is up.
In other cases the owner may want to take his mast down to inspect
rigging/electrical wiring or add equipment.
I never took my mast down while in Ontario as my marina had a travel-lift
and had no issues with this option.

WaIIy wrote:
On Sat, 15 Jan 2005 14:47:58 GMT, "Jim," wrote:
BillP wrote:
When we bought the boat there were only a few wedges in place, not enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite after
it sets?, does it allow some movement or does it harden as a solid rubber?

One of the guys in my YC seals the mast opening with a piece of line
jammed into place (ater adjusting the stays to give him proper rake),
then coats it with silicone. Since we have to drop the mast every year
for haulout, it seems to work well for him

Which brings me to a question. I know next to nothing about sailboats
and I notice in a marina near me (Cleveland) that some of the sailboats
take down the mast for winter and some don't.

Regarding the nuisance of taking the mast down, I would not like to have
my boat close to someone who did keeps the mast up, and is toppled over
by a strong wind. (In our harbour, everybody who uses a plastic tarp
lost theirs in the storm we had just before Christmas. I also saw some
tarp supports blown over, not to speak of small craft that were blown
partly from their supports).

Another thing is, if you leave the mast up, you have to loosen the
stays and shrouds anyway to prevent the stress on the hull from the
shortening of wire in cold, so the additional nuisance of taking the
whole thing out is not so big. And makes it easiedr to survey the whole
thing before the next season.

All cranes in my area can lift yachts with the mast up (provoding the
aft stays are removed), so that is not an impossibility. It also seems
that there are no regulations against keeping the mast up. If I were an
insurance official, I would make it illegal because of the increased
risks of toppling or stresses on the hlul. After all, the leverage
imposed by a mast is much more than without.
--
Mast wedges and the seal do not seem at all the same thing to me. Wedges
are there to take up stresses, and the seal to prevent leakage. If one
uses wedges instead of Spartite, one can easily change the position of
the mast, as trimming requires, by just moving the wedges. I understand
that this is impossible with Spartite.

Dag Stenberg

"Dag Stenberg" wrote in message
...
WaIIy wrote:
On Sat, 15 Jan 2005 14:47:58 GMT, "Jim," wrote:
BillP wrote:
When we bought the boat there were only a few wedges in place, not
enough
for proper support. I understand how the SparTite system works but is
there another system that would work? Say just filling the partner with
silicon, would this allow to much flexing? How firm is the SparTite
after
it sets?, does it allow some movement or does it harden as a solid
rubber?

One of the guys in my YC seals the mast opening with a piece of line
jammed into place (ater adjusting the stays to give him proper rake),
then coats it with silicone. Since we have to drop the mast every year
for haulout, it seems to work well for him

Which brings me to a question. I know next to nothing about sailboats
and I notice in a marina near me (Cleveland) that some of the sailboats
take down the mast for winter and some don't.

Regarding the nuisance of taking the mast down, I would not like to have
my boat close to someone who did keeps the mast up, and is toppled over
by a strong wind. (In our harbour, everybody who uses a plastic tarp
lost theirs in the storm we had just before Christmas. I also saw some
tarp supports blown over, not to speak of small craft that were blown
partly from their supports).

In the marinas around here, hundreds of boats are hauled and blocked with
the masts up. In 10 years I have only seen one boat fall over and that was
due to the sand erroding out from under a stand during a particularly
heavy downpour. Winds during the winter here can reach up to 60mph.
We have had 2 hurricanse roll through here with no toppled boats
either, winds up tp 70mph. I guess it is all in how the boats are blocked.

Another thing is, if you leave the mast up, you have to loosen the
stays and shrouds anyway to prevent the stress on the hull from the
shortening of wire in cold, so the additional nuisance of taking the
whole thing out is not so big. And makes it easiedr to survey the whole
thing before the next season.

I've never heard of doing that around here. We keep our boat in the water
as do many boaters. But nobody loosens the rig that I have even seen.

All cranes in my area can lift yachts with the mast up (provoding the
aft stays are removed), so that is not an impossibility. It also seems
that there are no regulations against keeping the mast up. If I were an
insurance official, I would make it illegal because of the increased
risks of toppling or stresses on the hlul. After all, the leverage
imposed by a mast is much more than without.

That may be the difference. Nobody around here hauls boats with a
crane. All the yards that do hauling have Travelifts, forklifts, or
railways.

Mast wedges and the seal do not seem at all the same thing to me. Wedges
are there to take up stresses, and the seal to prevent leakage. If one
uses wedges instead of Spartite, one can easily change the position of
the mast, as trimming requires, by just moving the wedges. I understand
that this is impossible with Spartite.

That is true, but I've never seen anyone actually move the wedges once they
are in position. Spartite doesn't leak which is it's strong point.

Dag Stenberg

Doug
s/v Callista

Dave wrote:
On 18 Jan 2005 09:00:27 GMT, "Dag Stenberg"
said:

Another thing is, if you leave the mast up, you have to loosen the
stays and shrouds anyway to prevent the stress on the hull from the
shortening of wire in cold, so the additional nuisance of taking the
whole thing out is not so big.

How does the coefficient of expansion of aluminum compare to the coefficient
of expansion of stainless wire?

Good point! I found the following values (in m/m.K) from different sources:

Al 23.5 E-6
Al 23.7 E-6 Steel 12 E-6
Al 22.2 E-6 Steel 13.0 E-6
that last source Stainless steel (304) 17.3
Stainless steel (310) 14.4
Stainless steel (316) 16.0

"The thermal expansion coefficient of aluminum near room temperature is
about twice that of steel (the exact values depend on the type of
aluminum and the type of steel, but for most types it's around 24 ppm
per deg C for aluminum and 13 ppm per deg C for steel)"

OK, so we'll believe that pure aluminium has nearly double heat expansion
compared to stainless steel.

Aluminium alloy 6063 T6: 22 E-6, Stainless steel (306) 17 E-6

Aluminium alloys
(LM 25) 22 E-6
(6061) 24 E-6
(6082) 23 E-6

So we can still believe that aluminium alloys have much greater thermal
expansion than even stainless steel.

Where does that put us? I suppose one can then argue, that when it gets
colder, the aluminium mast shortens more than the stainless steel
shrouds, so those should actually loosen. Apparently I have been misled
earlier by incomplete information....

Dag Stenberg

On 18 Jan 2005 12:31:23 -0600, Dave wrote:

On 18 Jan 2005 09:00:27 GMT, "Dag Stenberg"
said:

Another thing is, if you leave the mast up, you have to loosen the
stays and shrouds anyway to prevent the stress on the hull from the
shortening of wire in cold, so the additional nuisance of taking the
whole thing out is not so big.

How does the coefficient of expansion of aluminum compare to the coefficient
of expansion of stainless wire?

Thermal coeff of Aluminum is double that of Stainless, in round
numbers

Brian W

"Dag Stenberg" wrote in message
...
Dave wrote:
On 18 Jan 2005 09:00:27 GMT, "Dag Stenberg"
said:

Another thing is, if you leave the mast up, you have to loosen the
stays and shrouds anyway to prevent the stress on the hull from the
shortening of wire in cold, so the additional nuisance of taking the
whole thing out is not so big.

How does the coefficient of expansion of aluminum compare to the
coefficient
of expansion of stainless wire?

Good point! I found the following values (in m/m.K) from different
sources:

Al 23.5 E-6
Al 23.7 E-6 Steel 12 E-6
Al 22.2 E-6 Steel 13.0 E-6
that last source Stainless steel (304) 17.3
Stainless steel (310) 14.4
Stainless steel (316) 16.0

"The thermal expansion coefficient of aluminum near room temperature is
about twice that of steel (the exact values depend on the type of
aluminum and the type of steel, but for most types it's around 24 ppm
per deg C for aluminum and 13 ppm per deg C for steel)"

OK, so we'll believe that pure aluminium has nearly double heat expansion
compared to stainless steel.

Aluminium alloy 6063 T6: 22 E-6, Stainless steel (306) 17 E-6

Aluminium alloys
(LM 25) 22 E-6
(6061) 24 E-6
(6082) 23 E-6

So we can still believe that aluminium alloys have much greater thermal
expansion than even stainless steel.

Where does that put us? I suppose one can then argue, that when it gets
colder, the aluminium mast shortens more than the stainless steel
shrouds, so those should actually loosen. Apparently I have been misled
earlier by incomplete information....

This jives with what I have observed. Not so much that shrouds appeared
to be loose, but I have noticed occationally that forestays and backstays
appear a bit slack. I chauked this up to the fact that to be hauled with
a Travelift one often has to release either the backstay or forestay to fit
into the Travelift without hitting the crossbar. Once blocked, I assumed
that
the fore or backstay was not tightened as it would be for normal operation.

Dag Stenberg


Glad to learn something new and useful.

Doug
s/v Callista

Doug Dotson dougdotson@nospamcablespeednospamcom wrote:
"Dag Stenberg" wrote in message
...
... pure aluminium has nearly double heat expansion
compared to stainless steel.
Where does that put us? I suppose one can then argue, that when it gets
colder, the aluminium mast shortens more than the stainless steel
shrouds, so those should actually loosen. Apparently I have been misled
earlier by incomplete information....

This jives with what I have observed. Not so much that shrouds appeared
to be loose, but I have noticed occationally that forestays and backstays
appear a bit slack.

Yep, now I heard something from our club: somebody left the mast up, and
it started to wobble in the wind, putting more stress on the hull.

About the risk of toppling over - there seems to have been an occasion
in Cornwall about five years ago, when 50 boats toppled over, because
the gusts had rocked the supports, making them loose. They used logs for
supports, no cradle.

With the mast up, the rocking against the supports of the cradle will be
stronger than without the mast. I hear that one yacht in a marina close
by our place got one of the supports through the hull because of this.

So I remain happy with unstepping the mast for the winter.

Dag Stenberg

Dave wrote:
On 18 Jan 2005 20:08:50 GMT, "Dag Stenberg"
said:

Where does that put us? I suppose one can then argue, that when it gets
colder, the aluminium mast shortens more than the stainless steel
shrouds, so those should actually loosen. Apparently I have been misled
earlier by incomplete information....

Not really a matter of "one can argue." Should be pretty obvious from the
results of your research.

Yes, but I tried to make an allowance for unknown factors. Anyway, I
have learned that experimentation is more reliable than reflection.

Dag Stenberg

Dave wrote:
On Wed, 19 Jan 2005 00:52:07 GMT, Brian Whatcott
said:

How does the coefficient of expansion of aluminum compare to the coefficient
of expansion of stainless wire?

Thermal coeff of Aluminum is double that of Stainless, in round
numbers

Actually, it was a rhetorical question.

Maybe, but the same question was asked yesterday in our local newsgroup.

Dag Stenberg