Is there too much slack in my mainsail?

[shaant01]

Hello,

I own a Siren 17 and it feels like there is too much slack near the foot of the mainsail. It is attached to the boom. I am not sure how much slack is reasonable or if it would impede the sailboat. There is the option to lower the boom and that seems to stretch it out more, but I would rather have the additional headroom if it is all the same. I included an image of the mainsail; it is fully hoisted.

Thanks!

 

[kappykaplan]

The scallops on the luff would seem to indicate the sail may be too large for your boat. How old is the sail?

 

[Davidasailor26]

Pictures from some other angles would help, but the wrinkles don’t look great. I could think of three causes, though there may be other possibilities -

- the sail could be the wrong size like kappy suggested

- the bolt rope could’ve shrunk, keeping you from hoisting the sail as far as it should

- you may have raised the main while the sheet was still tight, keeping too much tension on the leech and keeping you from getting it to full hoist.

 

[shemandr]

No, no no! Something's wrong. I think the simplest thing to do is lower that boom. Headroom on a 17' boat is an illusion anyway. But I don't think that would even fix that sail.
The sail should be basically flat. Make sure the outhaul is tight and then some. Make sure reef line if it exists, vang, mainsheet are all slack. Tighten the halyard, wait and retighten it several times.
Then call a sailmaker and get a decent sail.

 

[shaant01]

The scallops on the luff would seem to indicate the sail may be too large for your boat. How old is the sail?

Thanks! I am not sure about the sails, but the sailboat is from the 80s.

 

[shaant01]

I wil

Pictures from some other angles would help, but the wrinkles don’t look great. I could think of three causes, though there may be other possibilities -

- the sail could be the wrong size like kappy suggested

- the bolt rope could’ve shrunk, keeping you from hoisting the sail as far as it should

- you may have raised the main while the sheet was still tight, keeping too much tension on the leech and keeping you from getting it to full hoist.

Thanks! The sail has plastic slides that feed into the mast. I am careful to release the mainsheet and boom bang when I hoist the sail. Aside from that, I could lower the boom and see if it is better? I may need to replace the sail otherwise.

 

[shaant01]

No, no no! Something's wrong. I think the simplest thing to do is lower that boom. Headroom on a 17' boat is an illusion anyway. But I don't think that would even fix that sail.
The sail should be basically flat. Make sure the outhaul is tight and then some. Make sure reef line if it exists, vang, mainsheet are all slack. Tighten the halyard, wait and retighten it several times.
Then call a sailmaker and get a decent sail.

Thanks for the tip! I will lower the boom and update soon. I remember when I had it lowered it seemed much better and I will retighten the halyard.

 

[Davidasailor26]

The sail has plastic slides that feed into the mast.

Sails with slides have bolt ropes sewn into the luff too. But if the very luff of the sail is as loose as the section with the wrinkles that’s probably not the problem.

 

[shaant01]

Sails with slides have bolt ropes sewn into the luff too. But if the very luff of the sail is as loose as the section with the wrinkles that’s probably not the problem.

The luff is fairly loose as well and it seems to rise to the top of the mast or almost. I think the sail is cut for the lower boom slot and so it is too loose when the boom is raised. I’ll lower it tomorrow and update the thread. Cheers!

 

[Joe]

Sails with slides have bolt ropes sewn into the luff too. But if the very luff of the sail is as loose as the section with the wrinkles that’s probably not the problem.

In the meantime, you can take some of the slack out of the mainsail luff by rigging, as best you can, some kind of "downhaul" or "cunningham". You could use the same fitting on the mast or deck that keeps your boom from creeping up. Use one of the luff's grommets, lowest one is better, or you may even notice a lonely grommet all by itself with no slider clipped on... that stray grommet was most likely used for that purpose. It's very common for small boats and beach cats to have non adjustable halyards... many, such as a Laser, have no halyard, the sail has a sleeved luff that slips over the mast like a curtain rod... then at the bottom of the sail a cunningham or downhaul is rigged up using loops tied into the line to give the thing extra purchase... you can do the same thing, yet it doesn't have to be as complicated because you're just setting it up to essentially shorten the luff.

Taking care of the vertical part is easy, what will be more difficult is the horizontal excess. If you're lucky there may be a reefing grommet in the leech (back edge of sail) that will allow you to thread a piece of line through it so the effort goes diagonally... down and back... to help get some of the excess out. You can be creative here.... it honestly makes no difference what it looks like... You will get more looks leaving it the way it is now, than trying to make creative changes. The other sailors will see your attempts as a guy who understands the sail doesn't fit......and you may even get some helpful, well intended suggestions we may not have thought of...

One of the other guys suggested a few more pics might help. I agree. Lay the sail out flat on the ground so we can see it entirely. Also take a picture of each corner...... NOT super close up... but a pic that shows a corner and 2-3 feet of the edges. The other shot that might help is how the panels and their seams are run... because that sail's cloth looks more like a cotton sheet... soft and pliable... so it would be pretty easy remove some ot the belly by re sewing some of those seams. A home sewing machine would be fine for the panels, and hand stiching for the new grommet on the leech is all you need... except you'll want to order some dacron thread and a couple of stainless steel grommets from a pretty cool resource... "Sailrite.com" Check out their website and ask them to send you a catalogue. They also have a lot of how to vids... you'll learn a lot. Okay.......... have fun. Sorry I got so chatty, but ....uh... that's my roll.... and I sensed your enthusiasm... which is all I need to get me going. heh, heh.

 

[shaant01]

In the meantime, you can take some of the slack out of the mainsail luff by rigging, as best you can, some kind of "downhaul" or "cunningham". You could use the same fitting on the mast or deck that keeps your boom from creeping up. Use one of the luff's grommets, lowest one is better, or you may even notice a lonely grommet all by itself with no slider clipped on... that stray grommet was most likely used for that purpose. It's very common for small boats and beach cats to have non adjustable halyards... many, such as a Laser, have no halyard, the sail has a sleeved luff that slips over the mast like a curtain rod... then at the bottom of the sail a cunningham or downhaul is rigged up using loops tied into the line to give the thing extra purchase... you can do the same thing, yet it doesn't have to be as complicated because you're just setting it up to essentially shorten the luff.

Taking care of the vertical part is easy, what will be more difficult is the horizontal excess. If you're lucky there may be a reefing grommet in the leech (back edge of sail) that will allow you to thread a piece of line through it so the effort goes diagonally... down and back... to help get some of the excess out. You can be creative here.... it honestly makes no difference what it looks like... You will get more looks leaving it the way it is now, than trying to make creative changes. The other sailors will see your attempts as a guy who understands the sail doesn't fit......and you may even get some helpful, well intended suggestions we may not have thought of...

One of the other guys suggested a few more pics might help. I agree. Lay the sail out flat on the ground so we can see it entirely. Also take a picture of each corner...... NOT super close up... but a pic that shows a corner and 2-3 feet of the edges. The other shot that might help is how the panels and their seams are run... because that sail's cloth looks more like a cotton sheet... soft and pliable... so it would be pretty easy remove some ot the belly by re sewing some of those seams. A home sewing machine would be fine for the panels, and hand stiching for the new grommet on the leech is all you need... except you'll want to order some dacron thread and a couple of stainless steel grommets from a pretty cool resource... "Sailrite.com" Check out their website and ask them to send you a catalogue. They also have a lot of how to vids... you'll learn a lot. Okay.......... have fun. Sorry I got so chatty, but ....uh... that's my roll.... and I sensed your enthusiasm... which is all I need to get me going. heh, heh.

Thanks for the info! I will look into the downhaul and some of these solutions as soon as I have more time. I live in Canada, so it is almost the end of the season here. I would rather not remove the sail yet, but I will update the thread once I have lowered the boom and see if that is much better. Cheers!

 

[Hayden Watson]

Thanks for the info! I will look into the downhaul and some of these solutions as soon as I have more time. I live in Canada, so it is almost the end of the season here. I would rather not remove the sail yet, but I will update the thread once I have lowered the boom and see if that is much better. Cheers!

It could just be the angle, but this sail does not appear to have a cringle for a flattening reef. Your best bet is lower the boom. It should be low enough that you have just a bit more height that you can raise the head when fully hoisted. The sail needs to have tension on the luff. Outhaul on the foot will also go a long way to making the main look like a real sail.
On many small boats, the luff is tensioned but hoisting the sail until it hits the mast head and then the boom is pulled downward to tension the foot.

 

[shaant01]

Hello! I wanted to update the thread. I have lowered the boom and tensioned the outhaul, but even now it feels as if there is too much slack. Here are three more shots of the sail. The first and third show the slack on the leeward side of the sail. I need to mess with the downhaul, as some of you have mentioned, or else replace the sail. Can someone tell me: is it normal for sails to puff out like that?

 

[shaant01]

It could just be the angle, but this sail does not appear to have a cringle for a flattening reef. Your best bet is lower the boom. It should be low enough that you have just a bit more height that you can raise the head when fully hoisted. The sail needs to have tension on the luff. Outhaul on the foot will also go a long way to making the main look like a real sail.
On many small boats, the luff is tensioned but hoisting the sail until it hits the mast head and then the boom is pulled downward to tension the foot.

Thanks! It does have an eyelet on the luff for reefing, if that is what you mean; I’m not sure if there is an eyelet for a flattening reef though. It has an outhaul on the foot but no downhaul at the moment. I will look into adding one soon.

 

[kappykaplan]

It looks like it's an old sail in need of replacement. Tks for posting the additional pictures.

 

[shaant01]

It looks like it's an old sail in need of replacement. Tks for posting the additional pictures.

Thank you for the help! If the sail is as old as the boat, then it’s more than 40 years old. I don’t know if the former owners ever replaced it. I think I will order new sails for next season. That’s the likeliest explanation. Cheers!

edit: I remember the previous owners told me they bought those sails, so I imagine they are not older than 5 or 10 years.

 

[Hayden Watson]

You will not know how blown out the sail may or may not be until you get tension into all three sides.