In-Mast Main Jamming Regularly

[bchaps]

My vessel has an in-mast furling system and no budget to change it. So I am not interested in another discussion of the Pros/Cons of an in-mast furling system.

What I have not found in my forum searches is adequate advice to reduce my jamming episodes. Yes, I know an in-mast furl is prone to jamming, but there are thousands of sailing vessels currently using in-mast furling and I'm sure many Captains have developed procedures to minimize jamming the main sail. I'm asking you to share how you have confronted this problem.

Discovered so far:

1. sail may require recutting to flatten. (yeah, kills roach)
2. Halyard tension affects wrinkling
3. Topping lift tension affects furling.
4. Keep the wind off the nose while furling.

I will appreciate your comments on techniques to furl the main without creating a wrinkled mess inside the mast.

Thank you,

Bill

[Bash]

In-mast mains are not "prone to jamming."
If it's jamming, the most likely reason is that you're doing something wrong.
Most common mistake is not having equal tension on the whole sail. Too much leach tension is just as bad as too much foot tension. Make certain the angle of the boom is right before you begin to furl.

Flattening the sail, via a recut, does not affect the roach. Flattening the sail changes the draft.

[Dockhead]

Cue the chorus of voices who, ignoring the request of the OP that he is not interested in the pros and cons of in-mast furling, will snidely insist that he got what he deserves for having in-mast furling in the first place, and go into a lengthy diatribe about why.

As Bash said: the system is not inherently prone to jamming. I have had exactly one jam in mine in going on a hundred days at sea, and that was due purely to my own inexperience.

What I found is that you need to be very careful about the angle of the boom -- on my boat, at least, the boom needs to be absolutely horizontal. The point is -- as Bash said -- to have equal tension in leech and foot so that the sail is smooth and flat as it's being hauled in. You can change the balance between the tension in leech and foot by changing angle of the boom with kicker and/or topping lift.

Second: be careful to keep some tension on the outhaul as you bring in the sail.

Both of these things are obvious and logical if you think about it -- the tension from the clew needs to be correctly aligned in order to keep the sail smooth as it is rolled in.

After my first (and admittedly traumatic) jamming experience, I have had no further problems.

I don't think there is anything wrong with bringing the head to the wind when you furl. I think I get a somewhat better furl this way, because the back tension comes all from the outhaul and is thus more controllable. But I can furl off the wind, too -- the system is not too sensitive to this, at least on my boat. Being able to furl or unfurl (reef or unreef) off the wind is one of the great advantages of the system.

If your sail is all blown out, then that could be your problem rather than improper furling technique. But if your sail is all blown out you have other problems as well. Replace it in that case.

[Hud3]

I never had a single jam on my Charleston Spar furler. Is that the brand IPY was using on your 1999 IP40? My boat was built in 2000, so I'm guessing we have the same equipment.

The two most important things to do, in my experience, are to keep steady, moderate tension on the outhaul, and to angle the bow about 10 degrees off the wind to allow the boom to line up with the roller in the slot so the sail goes in clean. In other words, angle the boom to make sure the sail doesn't rub heavily on the edge of the slot as it rolls in. I used a winch to roll in the sail so I could use my other hand to apply tension to the outhaul.

[Bash]

Originally Posted by Hud3

I never had a single jam.....

Same here, except that my mast is a Seldon. Had one on the previous boat for eight years without a jam, and the current boat is coming up on its 5th birthday without a jam.

You may want to hook up with someone who knows his/her way around that rig, and get a critique on what's going wrong. Unfortunately, sailmakers don't always know their ways around an in-mast furler.

[goboatingnow]

Outhaul tension ,that's the main reason you get jams. People don't put on enough. I find poor boom angle and halyard tension are factors but not major ones

Dave

[sailnautilus]

Had three different systems in ten years;
Dockhead is absolutely right:
1. Angle of boom
2. Outhaul tension

Good Luck!!!

[Lowcountry]

Have you tried contacting the previous owner of Charbonneau? His name is Blaine Parks, and he lives here in Charleston. I'd bet he would be more than willing to assist you.

[bchaps]

Thank you everyone. I have noted your recommendations and will place them into practice as soon as I'm back on the water.

Bill

[David_Old_Jersey]

Not being facetious - but have you read the manual?

[bchaps]

David Old Jersey...since you aren't being facetious, I must ask what manual?

The IP owners manual included with my boat covers nothing about boat handling, which isn't surprising.

Bill

[CarlF]

When I first got my boat with in-mast furling I had lots of troubles with jams. I tried all the standard things (boom angle, outhaul tension, sacrificing virgins).

Then I had rigger come look. He hadn't even gotten on the boat before he asked "Why do have so much prebend?"

It turns out that the previous owner had tuned the mast with a lot of prebend because that's what his old 'non-inmast furling" mast had looked like.

Once the rigger had straightened the mast (he left just a touch of prebend in to avoid pumping in a seaway) I never had another jam.

Carl

[David_Old_Jersey]

Originally Posted by bchaps

David Old Jersey...since you aren't being facetious, I must ask what manual?

The IP owners manual included with my boat covers nothing about boat handling, which isn't surprising.

Bill

I was thinking about the Manual for the In-Mast reefing (and not the boat itself). Am pretty sure that something like that would have it's own Manual / Users Guide - my toaster has and maybe even specific to an IP40.

Based on previous comments I did a quick Google on "Charleston Spar furler" (although no idea if that is your make) and came up with:-

Recommendations - furling masts - Charleston-Spar (not exactly wildly helpful - but every little helps )

What I was looking for was something like this PDF:-

http://www.c34.org/manuals/c34-inmast-furling.pdf

My guess is that the equivalent for an IP40 is much the same.

My thinking is that useful to know what the manufacturer wants - don't mean they always be right of course but gives a solid starting point to compare with what you are doing........of course hands on experiance from others is also useful

[wilsodf]

bchaps,

Who makes your mast. I have a US Spars and they have a known issue where the outer foil does not come down far enough and this causes the tack to come of of the mast and it usually jams when you furl the main back in. Neil Pryde came us with a fix that helped but didn't solve the issue 100%. The bast way to keep it from jamming was to keep the main halyard super tight.

The final fix was to have the sail maker add more luff tape to the bottom of the main and install an outer foil extension to the bottom of the inner foil right above the tack shackle. The requires ordering the part from US Spars and taking the furling unit apart. I am right in the middle of the install and will have our boat back in the water in a few weeks.

Anyone with a US Spars furling mast will probably have this issue.

[chuckr]

we have a seldon rig on our jeanneau and had a problem when we first started as i had the boom parrell to the main - raised it a bit and not an issue any more - we furl in all sorts of conditions and the main thing we find is keep tension on the sail as you furl it and we move the boom to starboard a bit when we roll the sail to give it a better angle of unfurling -
we have been out 4 years and no real issues at all with it and would never go back to traditional sail - love furling and unfurling from the cockpit
just how we do it and our thoughts
chuck patty and svsoulmates
rio dulce guatemala - leaving in 9 days for honduras