How much can you winch the halyard?

[delevi]

Back to the ongoing saga of poor mainsail performance. (This has been driving me absolutely mad.....now my 3rd thread on this...) After talking with a sailmaker and carefully inspecting my sail, it is quite likely that my boltrope did in fact shrink. It curls pretty nicely near the tack. I came out to the boat this afternoon and hoisted the main to see how much I can stretch it out. I have never used the winch on my halyard before but decided to give it a try. To my surpise, there was pleny of line I was able to winch in after I could not pull it any further with just my 200lb body. My concern is how much is too much? I gave it a good 4-5 revolutions, getting it quite tight, though I didn't see wrinkles in the luff and I could still wiggle the lower slides within their gromets. I think I could have cranked it some more, but I was afraid to break something. What do you guys think? Can a shrunken bolt rope be stretched or the sail shape problem be alievated by winching the crap out of the halyard, and if so, how much can the rig take?

Almost forgot to mention... I haven't sailed with this setup yet. I was experimenting with the boat on the trailer. I ran out of daylight to go out on the water and test it out.

[Gerald Gordon]

The boltrope in the is some kind of man made fiber. I don't think it shrinks. But it could be streched, I think.

[ALX357]

usually recommended to cut the stitching at the bottom of the bolt rope, not the sleeve stitching, but just the few stitches which go thru the middle of the boltrope diameter and sleeve, at the bottom of the boltrope, so it can ride up in the sleeve and let the sail unwrinkle. The bolt rope shrank while the sail stretched, so it needs to be cut free.

[Chip Hindes]

I always use the winch to tension the main halyard. Possibly because I do this, my bolt rope gets stretched pretty well every time I use it and after five years it's not a problem. (Sorry, I keep flashing on George's "shrinkage" from the Seinfeld show.)

Anyway, I watch the sail and only crank until the luff tightens up and the wrinkles disappear.

Since you're trying to stretch yours: rough numbers figure 2" diameter winch drum, 8" winch handle, total advantage 8:1; if you put 50 lb on the handle (I think a reasonable figure , a pretty hefty crank but don't use both hands or put all 200 lbs into it) something like 400 lbs tension total. That's 800 lbs total on the halyard cheek block at the top of the mast. Not sure what the block rating is but that's pushing it; my guess is the the rig can handle it OK, but I wouldn't go much higher.

I can't picture how cutting any of the stitching is not going to do some damage. Instead, if you have a protected area where you park and/or the wind is forecast to be low, I might try cranking it up, then bundling the sail against the mast as best you can, and leaving it tensioned for a day or two to see if you can get some stretch over an extended period under tension. I'd certainly try this before considering cutting anything.

[Tom Spohn]

ALX357 is correct. Cutting the stitches on the bolt rope at the tack can allow as much as 4 or 5 inches of stretch in the luff of the sail. I don't remember this being an issue on our X, but it definitely is an issue on the M.

Chip,
You don't cut any of the stitches that hold the sail together, just the few stitches that go through the bottom of the bolt rope. The bolt rope is there for folks that don't want slides, which I am guessing is about 0% of the M owners.

Other things that are easy to overlook. Make sure the boom is raised at the end when running up the main. Tension on the leech of the sail will keep the head from going all the way to the top. On our topping lift we had two clips--one for sailing and an upper one for raising the sail and keeping the boom up when anchored. For the same reason it is necessary to release any tension of the vang. We also found liberal doses of sail slide lubricant really helped get the sail all the way up without using the winch--although I always finished off the lift with a tweak of the winch.

[delevi]

Thanks.

Chip,

The Seinfeld reference to the shrinkage episode cracked me up. I was actually thinking about that when I wrote the post.

Alex & Tom,

I think I will take your advice and cut those stitches. About how far up from the tack shoud l I go & do I need to sew anything back up once I free up the bolt rope? Thans again.

[Moe]

Leon, I think this is what Tom is talking about:


Click on the image to view it at the original size

[delevi]

Moe, you rock! Diagram & all. How do you do it?
Thanks a lot, Alex, Tom, Chip & Moe.

I took my sail home to cut the stitches going through the bolt rope. I have a feeling this will solve my problem. Man, I sure hope it does. Now to give the sail a bath.... lots of dark stains on it from lowering it on a mudy deck. Can't wait to go sailing & try it out. Have to wait until I return from my thanksgiving trip to Chicago to see the in-laws, though.

Happy Thanksgiving everyone!

[baldbaby2000]

You don't cut any of the stitches that hold the sail together, just the few stitches that go through the bottom of the bolt rope.

Moe's diagram helps but I'm still a little confused as to how this works. In how many spots is the bolt rope sewn to the sail? If these bottom stitches are cut, does the bolt rope slide as the halyard is tightened? Is there a downside to cutting the bolt rope; ripping the sail, overly stretching the sail, etc?

I usually use the winch to tighten the halyard but notice that the bottom of the sail luff is never as tight as the top. I figure this has to do with the stresses being more at the top of the luff due to the force of the main sheet being transferred to the top through the sail.

BB

[Chip Hindes]

I usually use the winch to tighten the halyard but notice that the bottom of the sail luff is never as tight as the top. I figure this has to do with the stresses being more at the top of the luff due to the force of the main sheet being transferred to the top through the sail.

The tension should be the same along the entire luff. If the top of the sail is tighter, it's because you have excessive friction at the bolt rope/luff. If you have slides, one or more of them is sticking; if you don't the bolt rope has excessive friction. With either this can be caused either by lack of lubrication or by the sail track having a tight spot, possibly due to impact damage. Inpect the track for damage, and try some lube. I've never needed any, but Sailcote has been recommended and I believe some use parrafin wax.

[ALX357]

I don't think it is friction. Rather it is bunched at the foot where the bolt rope stitches have it gathered. Your halyard winching will not tighten the sail evenly when the sail's boltrope sleeve is effectively longer than the boltrope within.
The bolt rope is only stitched at the bottom and very top. Look at your sail and see for yourself to confirm. After cutting those stitches, the sail will relax, relative to the boltrope, and the boltrope will appear to shrink up into the sail, but it has already shrunk, or the sail stretched - that was the problem - now it will go where its end needs to be for its length.
Never intended to be a tension holding part of the sail, the bolt rope's purpose was to hold the sail luff into the mast groove. After cutting it loose from the foot of the sail, it will still do its job as well as before, which is nearly nothing - since you have slides, right ? but it will now allow the sail to be halyard tight the whole way up. If it bothers you enough, you could re-stitch the boltrope again, when it has arrived at its proper place, but then you might have the same problem again sometime in the future. Having it free doesn't seem to present any problem.
'Prolly won't need a winch at all to get enough tension, since the problem/reason you did need it before/ will now be fixed, and the sail will have even tension along the luff, provided your tack point and foot tension are correct. Fear not, cut the 'mother loose and be free again.

[Moe]

The reason that I could take that picture is that I've never cut that stitching. If you've tightened the halyard as much as possible, and the bolt-rope isn't tight at the bottom, snaking back and forth, the problem probably isn't bolt-rope shrinkage. That's what you have when the bolt-rope is tight and the sail is still baggy at the luff.

It's as Chip says, friction that's keeping the sail above it from going up if you can't get the bolt-rope tight. This can happen even with slugs, especially if you have the prescribed amount of bow in the mast. Try lubrication. Some use SailKote, some use beeswax. I used Liquid Wrench Dry-Lube with PTFE as recommended by Frank C.

[Frank C]

Be sure you have no stresses on the mainsail - no wind, no vang, no mainsheet ... and as Alex writes above, you should not need a winch on the main halyard.

Larger boats need halyard winches because the sail is so heavy, and/or friction of much longer luff length ... that's not our case. If you don't have a Mate to hold bow-on-wind, just make sure the boom is free to swing and you should easily pull the main aloft. I think bolt rope shrinkage (or interference by the wind) explains 95% of luff wrinkles on the mainsail (and the remaining 5% are caused by an OVERLY taut main luff).

[adm]

I would not recommend cutting any stiches to free the rope unless absolutely positive that it shrunk somehow and it is very unlikely with modern man made materials. It is part of sail design, that bolt rope is shorter then sail by few percent to accommodate tension which need to be put on it when sail is hoisted. I do not have Mac but all boats I sailed big and small required that you put considerable tesion on halyard. It is needed to remove wrinkles. Normally for ~200 sq ft main it would be around 150 - 250 lbs. Beyond that you may have problems but not before. It can be done using winch or more traditionally by half cleating halyard, putting your foot agaist mast and giving halyard considerable side pull, then taking up created slack then repeat until set right. It has been done like that for eons. It is the reason that halyard should not strech by itself so tension remains like you set it up. If you have Cunningham it will be almost useless when main has wrinkles. It needs to add additional tension on the sail to change its shape and not to remove wrinkles.
Some already pointed put the need to raise the end of boom to ease tension on the leach as well as using some lubrication.
I would like to point out that sail needs to be set tight over the boom by outhaul too.
I noticed that most pictures from sailing adventures published on this site shows sails set with way too many wrinkles.

[ALX357]

Beg to differ.
Modern materials included, sails do stretch, or else they would last forever. It is common knowledge that sails lose their shape, from being stretched by wind, and by halyards.
On a Mac, it makes no sense to speak of tension on the bolt rope at all, it is not there to take tension. It is not connected to the tack nor head directly, and it is only held in the sleeve at the two ends by stitches. You can see that if the bolt rope were designed to take tension directly, the halyard shackle would have to be INSIDE the mast to be inline with the boltrope. Same for the tack at the gooseneck. Obviously the boltrope is not directly inline with the tension between the halyard / head and the tack. The sail luff behind the mast takes that tension and is reinforced with several layers along that span. The absence of that direct tension on the boltrope lets the sail stretch comparitively more. Especially if you are over-winching it on a regular basis.
Using slugs does not change that, they just move everything back further.

I was advised to cut the rope's stitches on my 5 year old sail, After I did, it went way up iinto the sleeve, about 7 inches, There was not that much usage wear, no damage, no fraying, just that shrunk rope/stretched sail.
Numerous other Mac Owners have found this out also, and dealers know about it too.

Racing boats have Cunningham rigs, Mac's don't need them.
Think also about the smaller diameter of the boltrope compared to the halyard.
If you constantly put 150 to 200 lbs. tension on your sail, you will stretch it even more. Just pull the halyard until the sail looks tight/right. in light air you need even less tension on the halyard. Both too much and too little tension will screw up the sail shape.
As mentioned by others, make sure the boom's weight is lifted via topping lift, boom-kicker, or by hand so the halyard isn't trying to lift the boom too.