Why is my sail coming apart?

Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
So I went out for a midwinter sail the other day. Since the wind was forecasted to be light, I shook out the reef from the previous sail. (I frequently leave a reef in because the boat seams to balance much easier with the first reef in the main.)
Upon close inspection, I noticed the sail separating from the grommet at the sail slug.

Torn Sail slug.jpg

Trying to figure out why this is happening has me puzzled;

Could it be that leaving the reef in without halyard tension allows the clew reefing line to slide the sail aft slightly?

Should that first slide shackle be just a little bit longer or should the reefing hook be a little further foward ?

Or is it just time to buy a new mainsail?

Here is a pic of my main for those that know how to tell by looking at the sail shape.

Sail Trim.jpg

This is close hulled in 10 - 15 knots with the main pulled tight, traveler to windward, Cunningham off and the outhaul set to moderate. (ignore the windex, I still haven't gone up the mast to straighten it out yet)
 
Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
It looks like time to get a new sail. How old is it?

-Will (Dragonfly)
It has some hand written numbers near the head of the sail, one of the numbers is 1991. Although the PO hadn't used the boat much before I bought it two years ago.
 
Jan 4, 2010
1,037
Farr 30 San Francisco
I think the reefing line puts some backwards pressure on the sail slugs. Maybe a sailmaker can rescue it but if it really is 30 years old.... Looking at your sail it looks like the draft is quite far back
 
Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
Age is not necessarily a factor of use. Years take their toll, especially with ill use and poor storage. Most equipment enjoys use more than disuse or misuse. I would consider replacing it.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Unfortunately, and as others have mentioned the sail looks like it is past its expiration date. UV takes a toll on sails and the tear looks like UV damage to the fabric. A temporary repair could be made, but it would be just that a temporary repair.

The good news is that now is a good time to order a new sail. Lofts often give discounts for winter work, however, the window on those deals may be closing soon.
 
Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
The good news is that if you do replace the sail, the new one will likely balance much better even without the reef.
True. With the draft moved forward, the sail will deliver more power with less weather helm.
 
Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
True. With the draft moved forward, the sail will deliver more power with less weather helm.
That is what I am hoping. It is satisfying to get conformation prior to spending the amount of money a new sail will cost.
 
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SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
The slug should be removed from the track because it can't restrain the tension you have on the foot of the sail . Do you have a gate that would allow you to disengage that luff slug?
 
Feb 10, 2004
3,917
Hunter 40.5 Warwick, RI
That is what I am hoping. It is satisfying to get conformation prior to spending the amount of money a new sail will cost.
Check Mack Sails in Florida. In the past they have had very good winter pricing, but you may need to act fast. I bought two sails from them; one a very special cut for a furling boom, and they fit perfectly right out of the box. Read their build plan on their website. I did a lot of comparing but decided that Mack had a superior quality for less money. But everyone has a favorite- you may have a preference of your own.
 
Mar 26, 2011
3,399
Corsair F-24 MK I Deale, MD
The problem--which is far too common--is that the horns are the wrong place. They need to be farther forward. The quick cure is to take the tack off the horns and lash it TIGHT to the mast and boom. The tack needs to be in-line with the luff and it is not. There should be very little outward pull on the slug.

You could remove the slug, but then there sill be pull on the next one. Move the tack forward.

Yes, the sail does look stretched. But you still need to address the tack location problem.

I've had several boats where I kept a line or strap at he mast to lashing reefing tacks forward. This is done on a number of classes.

---

Edit: Judy (below) is obviously correct. The right long-term solution is to have the sail made to accommodate this. I would not bother on this old sail, but provide the hook location to the sailmaker for the new one. Short term, I would take the tack off the hooks and lash it in the correct position.
 
Last edited:
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Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
So I went out for a midwinter sail the other day. Since the wind was forecasted to be light, I shook out the reef from the previous sail. (I frequently leave a reef in because the boat seams to balance much easier with the first reef in the main.)
Upon close inspection, I noticed the sail separating from the grommet at the sail slug.

View attachment 173413
Trying to figure out why this is happening has me puzzled;

Could it be that leaving the reef in without halyard tension allows the clew reefing line to slide the sail aft slightly?

Should that first slide shackle be just a little bit longer or should the reefing hook be a little further foward ?

Or is it just time to buy a new mainsail?

Here is a pic of my main for those that know how to tell by looking at the sail shape.

View attachment 173405
This is close hulled in 10 - 15 knots with the main pulled tight, traveler to windward, Cunningham off and the outhaul set to moderate. (ignore the windex, I still haven't gone up the mast to straighten it out yet)
Yes, you are right that the reefing hook on the boom and reefing ring on the sail is not pulling the sail far enough forward. The grommet for the slide that is immediately above the reef is being pulled aft.

A sailmaker can fix this for you very simply, by moving the webbing and ring for the reef further aft, so it lines up with the reef horn better. a new grommet can be installed above the torn one, or the old one removed/luff patched and a new grommet installed. It's a quick fix. Less than $100.

A mainsail is usually custom built to fit the mast and boom fittings. But in this case, the sail is not (presently) compatible with the boom, (perhaps because of DIY alterations to the sail?). A good sailmaker would have known better than to do that. Or maybe it was made without a full set of measurements

Looking at the sail, my spidey-sailmaker sense is tingling.... something's up with that sail. I suspect there may be more that one problem with the sail.

Its unusual to use nylon shackles to attach slugs to a mainsail for a 30 foot boat that weighs 9000 pounds. Usually the slides are attached with webbing (or metal shackles) Compared to the high level of construction elsewhere on the sail, those plastic shackle don't fit and suggest that a DIY-er might have modified the sail.

In any event, longer shackles for the slugs all the along the luff would also improve the alignment between the reef hook and the slugs. It might not be perfect though, and you need perfect alignment (within a 16th of an inch or so)

What does the gooseneck look llike without the sail attached. ?

And yes, the draft of the sail looks very deep all the way from foot to head. Its well past it's prime, shapewise. If your budget allows, get a new one from a reputable sailmaker.

But if you have to use what you've got for a while, a sailmaker could get you through another season by moving the webbed-on reefing ring on the sail and repairing the tear in the luff.

Judy B
 
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CarlN

.
Jan 4, 2009
603
Ketch 55 Bristol, RI
That sail is blown out. It eventually happens to all dacron sails. The draft is so far back that you are getting less forward force. Instead it is causing the boat to heal more which unbalances the helm - likely part of the reason you reef earlier.

Buy a new sail. You won’t believe the improvement. Mack is a great sailmaker (my sails are from Mack) but probably not needed for your daysailing needs. I’d consider one of the Asian lofts like Rolly Tasker. Stick with dacron cloth but don’t get the lowest grade.

 
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Aug 2, 2009
637
Catalina 315 Muskegon
Check Mack Sails in Florida. In the past they have had very good winter pricing, but you may need to act fast. I bought two sails from them; one a very special cut for a furling boom, and they fit perfectly right out of the box. Read their build plan on their website. I did a lot of comparing but decided that Mack had a superior quality for less money. But everyone has a favorite- you may have a preference of your own.
I have purchased a few sails from Mack. However, my last two orders were made in the Fall, and they totally forgot my orders and had to rush them out in out in the spring. The most recent order was a main for my Catalina 28, and I received it with problems they were slow or unwilling to resolve. I talked directly with the owner several times, and the conversations were absolutely bizarre, with my having to repeat things over and over. I finally had to make the corrections to the sail without their help. After these experiences I will never do business with them again, even though I like the fact that they are made here in the U.S. and are reasonably priced. YMMV, so not telling anyone what to do other than keep tabs on them and don't be surprised when goofy stuff happens.
 

SG

.
Feb 11, 2017
1,670
J/Boat J/160 Annapolis
Sail Trim.jpg


This is close hulled in 10 - 15 knots with the main pulled tight, traveler to windward, Cunningham off and the outhaul set to moderate. (ignore the windex, I still haven't gone up the mast to straighten it out yet)


Cowpokee,

Do are you using you boom vang? Also, regardless of what you say about your Windex, you don't look like to me that you're pointing-up (close to the wind) in this picture. To me, I think you have

I can't believe that your sail is this really this "baggy" that the point of maximum draft is this far aft.

Can you pull the out haul tight and flatten the main, tighten the vang down, point up so your apparent wind is about 30-35 degrees APPARENT, make sure you have the halyard tight or add a little Cunningham, leave the traveler in the center of the boat, tighten the sheet down hard, and then take a picture looking up. Make sure the leech line isn't complicating your ability to flatten the sail. (The leech line is best left to take the "flutter" out of the leech of the sail, generally not much else. If it's too tight it can screw things up, more than help. Ease it off so that it's not a factor. If the wind is blowing and the leech starts to flutter, just tighten it enough to stop the flutter. In light air, leave it loose enough to be out of the equation.)

I'd also like to see a picture from the boom looking back at cockpit from the mast area showing the relationship of the boom, dodger, traveler, and vang.

I am not suggesting that your main "doesn't owe you anything", be ready for others to recycle, or suggest it ready for prime time on the race course. However, I'd like to be able to see what the thing looks like when you try to trim and shape it somewhat differently.


 
Nov 26, 2012
1,653
Hunter 34 Berkeley
With the traveler to windward that sail does not look that bad to me. The telltail sign of a blown out main is a diagonal wrinkle. I do not see that.
 
Mar 26, 2011
3,399
Corsair F-24 MK I Deale, MD
Sail Trim.jpg


This is close hulled in 10 - 15 knots with the main pulled tight, traveler to windward, Cunningham off and the outhaul set to moderate. (ignore the windex, I still haven't gone up the mast to straighten it out yet)
I think the OP knows the sail is mis-trimmed--he was busy taking pictures.
  • The head is under-trimmed, as indicated by the Windex. Look closely and you will see the leach is blown to windward. Thus, you can gauge draft position by that, since the shape is distorted by backwind.
  • As you go further down, the draft is aft of 50% and too full. The sail is stretched. You will get more helm, more heel, and it won't go to weather as well. The OP needs to consider if that matters to him. It may not.
  • The lower sail is probably over trimmed. But this also depends on what the genoa is doing and I can't see that.
  • I can't see the foot. The luff looks straight. I won't judge cunninham and outhaul tension because I can't see enough.
The true wind is probably just forward of the beam and he is reaching. The sail will produce more power with similar heel if he lowers the traveler and tightens the sheet, matching the twist of the sail to the vertical twist in the wind. The genoa will also require lead adjustments. But not everyone is a sail trim maven. I would add leach telltales; they aren't just for racers.