Sail shape - what am I doing wrong?

[romandesign]

I have a 1989 Mac 26D with "newly reconditioned sail" as previous owner told me. It's my first boat, I have it for 2 years now but I just can't get the sail shape that's tight enough. It's baggy, no matter what I do. Sails look really good up close, almost new to the touch and feel, but they have been "reconditioned" somehow so maybe they are too worn out, or maybe I'm just not doing something right. Maybe it's the bolt rope that I should cut and tighten? I added a block to the clew outhoul and tightened it as much as I can. I also tightened main halyard as much as I could withouth fear of breaking something. I have added a DIY boom vang (the boat didn't have one). It works, but the sail is still not tight. Can anyone tell me what's the problem? Judging by the wrinkles, there's definitely something not tight enough, but what? Is it the sail or the running rigging? The foot seems to be tight. Vertically it might not be tight enough but a this photo the main halyard is as tight as I can make it - it runs to cockpit via two blocks and I can't get it much tighter by hand. It's not built to be used with a winch because I can't lock it that way and free the winch, so I tighen it by hand but really as much as I can.

Here are the photo that's stitched from seveal phone photos, to give an idea of the whole sail, and a couple of individual photos. I welcome all advice.







The line running to the reefing grommet is my DIY easy reefing system - the problem was there before I made it, so it doesn't interfere. The loose steel wire in front of mast is from the mast raising system. I also see that lazy jacks are getting in the way a bit, but they serve as a topping lift so I don't want to get rid of them if possible, unless they are causing the problem, which seems unlikely. When I look at other boats, their sails are much flatter. I literally have a zero budget right now, so new sails are not an option at all. I'd like to try and fix these ones. I tried more and less tension of upper and lower shrouds and backstay to get more or less mast bend, but I can't see any difference in sail shape, althout I've been doing it blind, so not sure if tension and bast bend is OK. Last time (in the photo) upper shrouds were definitaly too slack - I tried it to get less mast bend hoping it would help sail shape - it definitely didn't. And previously some people told me "you have quite a mast bend!" so it definitely was there. But it doesn't make a pronounced difference either way.

[sailboatmike]

I cant see the photos so hard to tell, if you have a bolt rope, shrinkage could well be a issue.

But here is a tip, your sails dont have to be dead tight, thats only for high winds, in lighter stuff you back off the outhaul and relax the main halyard slightly.

Overly tight sails cant form the correct shape to be aerodynamic.

And the main use of the vang is to take the twist out of the top of the sail.

Just a thought, have you released the topping lift?? Thats a regular thing I forget until I think why is my main so baggy and then I curse myself for being so stupid

[romandesign]

I've updated photo links - can you see them now? My problem is exactly in stronger winds when I do want a tighter sail - I can't get it tight enough.

I don't have a topping lift, so there's nothing to release. I have a clip at the boom's end to clip to backstay when sail is down, and I have lazyjacks that act as a topping lift and don't let the boom to sink too low when sail is not holding it.

[grady]

Reconditioned sail is cleaned and treated. They can not reverse stretch/“bolt rope shrinkage” tune it the best you can and increase back stay to flatten in higher winds. If it still bothers you buy a new sail.

[Azzarac]

It's hard for me to tell if it is the photograph or maybe the "stitching" of multiple photos but here is what I would check first. Bolt rope length as mentioned before. The first photo looks like you have excessive mast rake towards the aft of the boat. I'm going to assume your boom isn't actually bent in the middle as the photo makes it appear. Your lazy jacks may be too tight under sail. You should have ample slack in the line once you set the sail as to not interfere with, or chafe on, the sail.

[romandesign]

It's hard for me to tell if it is the photograph or maybe the "stitching" of multiple photos but here is what I would check first. Bolt rope length as mentioned before. The first photo looks like you have excessive mast rake towards the aft of the boat. I'm going to assume your boom isn't actually bent in the middle as the photo makes it appear. Your lazy jacks may be too tight under sail. You should have ample slack in the line once you set the sail as to not interfere with, or chafe on, the sail.

It's the photo stiching giving super wide angle perspective distortion. Mast rake is the angle of the mast, not the curve (bast bend), right? I've never measured it actually. But it shouldn't affect sail shape I think, if it's too steep the boom would be lower and there would be more weather helm but not sale shape related I think... Boom is straight, it's the same perspective distortion

Lazy jacks are too tight. I wonder how I can make them more slack... They were added by previous owner and they help as a topping lift so raising and lowering the sail is easier. Although the batten often gets on the wrong side of lazy jack lines and I have to make 2-3- attempts at raising the sail before it gets in the middle. I already clip the last line closer to the mast to avoind that, but it's still too tight. Not sure how I can make them slacker when I raise the sail... Lower part are bungee chord so it gets tight. Maybe I shoudl replace it with a regular nylon rope or something? Make them tight when boom is lower, so they are slack with sail is raised and boom is at 90 degrees.

[romandesign]

Reconditioned sail is cleaned and treated. They can not reverse stretch/“bolt rope shrinkage” tune it the best you can and increase back stay to flatten in higher winds. If it still bothers you buy a new sail.

I don't know much about sail tuning, but thinking geometrically thightening backstay would lead to more mast bend, so it should make the sail more bagy, not less. However I did read that increasing mast bend flattens the sail. I don't understand how it works though... Also, my backstay is not adjustable at all. There's not even a "two plates with holes" as there are on the sidestays, just one plate and a bolt to attach it to a deck plate. I just get it as tight as I can during rigging, but there is no fine adjustment, and not at all when I'm sailing.

I think I will try in winter to cut the vertical bolt rope free and re-stich it at a new place to see if it helps...

[Tomfoolery]

I started a thread on that subject a while back, but with the Photobucket shenanigans, all the pics are gone. But in short, cutting the bolt rope stitches at the bottom made a big improvement on a stretched sail. Still not a new sail or anything close to that, but better. Or less bad.

http://www.macgregorsailors.com/forum/v ... =8&t=23552

[romandesign]

I started a thread on that subject a while back, but with the Photobucket shenanigans, all the pics are gone. But in short, cutting the bolt rope stitches at the bottom made a big improvement on a stretched sail. Still not a new sail or anything close to that, but better. Or less bad.

http://www.macgregorsailors.com/forum/v ... =8&t=23552

I'd love to see those pics and video, to compare to my sail... I wonder if I have to hoist it to get the rope to move, or I can do it at home in winter time by hands...

[Tomfoolery]

I'd love to see those pics and video, to compare to my sail... I wonder if I have to hoist it to get the rope to move, or I can do it at home in winter time by hands...

I updated the photos, which was made easy due to photobucket showing the path on my computer to the file plus the file name. The last one was a screen grab, but I had filed the sketch where I could find it, so again it was easy to do another screen grab and upload it.

If I were you, I'd cut the stitching at the bottom now, hoist the main and sail on it while you can. It's only a few stitches at the end of the bolt rope. I didn't resew mine, by the way.

Hope that helps.

[DaveC426913]

Those lazy jacks are so taut you could play a tune on them.

You can see the jack lines pressing on the curve of the sail, and all the resultant wrinkles fanning out from them.

You need a fair bit more slack so they don't touch the sail when you release them. They should flop freely when released. (You do release them when flying sail don't you?)





Also, I've never seen a lazy jack configuration quite like that.
Not sure if that might be contributing to why they're so tight.

[Chinook]

Easy way to slacken the lazy jack lines is to run the top of the lazy jack lines through small blocks high up on the mast. The lines can be secured to cleats lower down on the mast. That makes it quick and easy to loosen the lines when you want to sail, and tighten them back up when you've got the mainsail stowed in its cover.

[Azzarac]

I started a thread on that subject a while back, but with the Photobucket shenanigans, all the pics are gone. But in short, cutting the bolt rope stitches at the bottom made a big improvement on a stretched sail. Still not a new sail or anything close to that, but better. Or less bad.

http://www.macgregorsailors.com/forum/v ... =8&t=23552

Hey Tom,
Earlier today I made a post under the "Photobucket is ruining this site" topic that may eliminate the hotlink issue with them not allowing others to view photos. Here are the links I posted:

I stumbled across an interesting extension for the Chrome browser that fixes the photobucket hotlink issue. Basically it re-directs the URL causing Photobucket to think it is being accessed directly. You can find it here at: https://chrome.google.com/webstore/deta ... apbifiaedg They also have a patch for Firefox users at Firefox/Android version: https://addons.mozilla.org/en-US/firefo ... bucket-fix

Hopefully we can return to enjoying this fabulous website as it was before Photobucket got greedy.

[Tomfoolery]

Unfortunately, I've already deleted my entire account in a fit of annoyance. So while I have all the originals on my work machine, the only way I'm going to fix history is to open and edit history.

[romandesign]

I updated the photos,

Thanks a lot! Really helpful.