In-mast furling - incorrect boom angle can make unfurling *very* difficult

[jwshukis]

I have a B40 with in-mast furling. Unlike some earlier boats, the mast
slot is more than wide enough and I've never had any problem furling
or unfurling the mainsail... until last week.

That time, the top third of the sail got jammed in the mast while
pulling the outhaul line. It took me about ten minutes of anxious
fiddling to to get it undone and working properly. At times, I
wondered if I would end up pulling hard enough to damage the sail.

I then spent quite a bit of time figuring out what went wrong. I think
I discovered the cause.

I believe that the people who tuned my rig the week before loosened
and then re-tightened the topping lift. However it happened, that day
the boom was angled upward, with the outward end raised some 8-10
inches above the mast end. With the outward end raised, more of the
outhaul tension went to pulling the lower part of the sail out of the
mast and less went to unrolling the top part, causing the "axle"
around which the sail is rolled to twist and creating a series of
folds that got hung up in the mast slot.

Later, after re-adjusting the topping lift, I furled and unfurled
several times to see if the problem would return. It didn't. I then
elevated the boom as before and was able to duplicate the problem.

My take-away lesson - and I'm curious to see if anyone else has had
the same experience - is that a boom angled up can interfere with
unfurling. Anyone out there who has unfurling issues, check your boom
angle.

Jeff

[Ted Weitz]

Although I don't have a furling main, I would assume the rule for furling mains is like that of for traditional mains -- the topping lift is primarily for keeping the boom from sagging when the sail is up, but should have no tension on it at all when under sail.  My impression has always been that any tension at all on the topping lift causes bad sail shape -- the sail should be the only thing holding up the boom while underway.  Is that different for furling mains?

Ted Weitz
Beneteau 323 "Gossamer Wings"
Three Mile Harbor, East Hampton, NY

--
Ted Weitz
tm...@columbia.edu

[Rick Donovan]

Ted
we have had discussions on the list in the past where it has been
determined that for the roller furling mains, the topping lift or
more precisely the angle of the boom relative to the mast is an
important adjustment to make the system work well, consistently.

Jeff described it pretty well and then confirmed that the angle of
the boom is a key adjustment. when he tightened the topping lift,
making the the outboard end of the boom to high, the problem returned.

for those of us sailing with the Classic main, the topping lift is
used to prevent the boom from dropping down to low, onto your dodger
for instance. sailing with tension on the topping lift can have an
effect on the leech if the topping lift is to tight and the main
sheet is in hard as you stated.

Rick Donovan
Biddeford, Maine

[Ted Weitz]

Rick -
Thanks for the clarification.  Us old fuddy duddy traditional main users are not quite up on this issue,

--
Ted Weitz
tm...@columbia.edu

[Scott]

make sure you loosen the vang! I was having trouble furling/unfurling
the main in certain situations. Was difficult getting the right
outhaul tension. Then I realized that the vang was really tight, and
boom was too low and couldn't pull outhaul to the end. Loosened vang,
easy to move outhaul, then tightened vang.


>

[bill n]

Don't you have the rigid vang on the 40? Topping lift isn't really
necessary?

[pegasu...@aol.com]

Yes I found that you have to have the topping lift and mainsheet in place when furling and infuring the mainsail to keep the boom hoizontal

---

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[PaulM]

I have a 393 with furling main and I used to have problems until I was
shown the following technique:

1. Keep the topping lift so that the boom does not hit the bimini. The
angle of the boom is NOT important at this point IF you do the
following when furling and unfurling ..
2. Point into the wind
3. Ease the sheet and vang considerably and then lock the sheet down.
(The boom may swing but that is ok if you are into the wind)
4. Unfurl with back pressure on the furling line. Furl with
backpressure on the outhaul.

Rationale:
As the sail comes out of the mast (or goes in) the boom finds its own
level or angle to horizontal, because the vang and sheet are eased and
the sail brings the boom up as necessary with the foot and leech
pretty much balanced with equal pressure. This approach seems to
greatly reduce and/or eliminate jams on my boat. The problems before
were due to the tension between the sheet and topping lift and trying
to find the correct angle for the boom. And the balanced pressure on
the foot and leech are important for smooth operation. Anyway, seems
to work.

======================================

On Jan 3, 4:06 pm, pegasusgof...@aol.com wrote:
> Yes I found that you have to have the topping lift and mainsheet in place when furling and infuring the mainsail to keep the boom hoizontal
>
>
>
> -----Original Message-----
> From: Ted Weitz <ted.we...@gmail.com>
> To: Benetea...@googlegroups.com
> Sent: Mon, 24 Nov 2008 10:17 pm
> Subject: {Beneteau Owners} Re: In-mast furling - incorrect boom angle can make unfurling *very* difficult
>

> Although I don't have a furling main, I would assume the rule for furling mains is like that of for traditional mains -- the topping lift is primarily for keeping the boom from sagging when the sail is up, but should have no tension on it at all when under sail.? My impression has always been that any tension at all on the topping lift causes bad sail shape -- the sail should be the only thing holding up the boom while underway.? Is that different for furling mains?

>
> Ted Weitz
> Beneteau 323 "Gossamer Wings"
> Three Mile Harbor, East Hampton, NY
>

> tm...@columbia.edu- Hide quoted text -
>
> - Show quoted text -

[Sal]

Greetings,

I have a 352 that had furling issues. The slot in my mast is narrow.
The previous owner told me that he never pulled the sail completly out
of the slot because he had problems furling the main. In additiion, I
had to use a winch to unfurl and furl the main. Something was
obviously wrong.

At first I suspected the boom angle. For this discussion the boom
angle is the angle between the boom and the mast that the sail
occupies. I found some information on the internet that said the boom
angle should be 90 degrees. Mine was not, it was less. My boat has a
bimini and I could not lower the boom. I was forced to seek
professional help. I went to a sail maker and I learned that the
angle between the mast and the boom should be about 87 degrees. MIne
was, so the boom angle was not the problem. The sail maker came to my
boat and inspected my sails. He quickly identified the problem. He
noticed that original sail maker used the wrong fabric at the head and
tack or the sail. There was to much fabric and that cause the sail to
bind and jam in the slot. He thinks the original sail maker used a
head and tack for a standard sail and not a reefing sail. Apparently a
reefing sail uses thinner and stronger fabric. Fixing that solved the
jamming problem.

I found a rigger who had lots of experience with in mast furling. I
learned that friction in the furling system was caused by 1) the
furling line and 2) the sail track and car. Over time the furling line
expanded. The expansion causes friction between the the drum, it is
actually more of a lead screw than a drum, and the rod that keeps the
line in the gooves on the lead screw. If you look inside the slot you
will get a better picture of what I am trying to say. The rigger
replaced the line with a new and smaller diameter line. He then inline
spliced a larger diameter line to to insure that the line would work
well in the winch. He replaced the track and car with Harken
equipment. The new car has ball bearings which made a big improvement
over the original track and car.

I costs a few dollars fix the problems, but I have never regretted it.
I've had no problems since. We get heavy winds on San Francisco Bay
and the last thing I want to be doing is struggling with a jammed
sail. Especially when my wife is aboard.

I hope this helps.

Sal Caruso
Beneteau 352
Boston Accent
Sausalito CA

[Leonard]

Sal:-
Who did you consult with regarding the "Sail Maker" and "Rigger". I have a
Beneteau Oceanis 361 and am berthed at 'Marina Bay' in Richmond.
Tranquillity

----- Original Message -----
From: "Sal" <sa...@sonic.net>
To: "Beneteau Owners" <Benetea...@googlegroups.com>
Sent: Sunday, January 04, 2009 9:32 AM
Subject: {Beneteau Owners} Re: In-mast furling - incorrect boom angle can
make unfurling *very* difficult

[Sal]

Hello Tranquility,

The sail maker was Robin at Hood Sail loft in Sausalito and the rigger
was JP of JP Rigging also in Sausalito. I have their phone numbers if
you cannot find them on line or iin Lattitude 38.

Sal
Boston Accent

[Leonard]

I would appreciate their phone numbers if it is not too much trouble!
Thanks
Leonard