Mainsail Trim

[mhinnc]

As you can see in the image, slugs hold the sail to the mast except for the first several feet above the boom. This results in a misshaped sail.


This image shows, at the bottom-most "typical" slug, the sail creases and that crease extends to the clew. Along the foot the sail droops over the boom several inches.


Below the bottom slug are two slugs with a line going through them. How would that typically be adjusted? The main halyard is pulled tight as it will go, yet the slack appears as shown. Thanks for any/all help.

[Don C L]

We had another thread on this topic not too long ago. I'll see if I can find it. In the mean time those lines are called jack lines and they are there to help keep the sail managed when you put in the first reef. It allows you to furl the main without it being all bunched up at he mast. Your main, if it truly is hoisted all the way up, must be the wrong size for the boat. I suspect something is holding it up from being fully hoisted though. Can you look up to the head when it is hoisted with binoculars and see if it is all the way up, or does it stop somewhere close to the top?

By the way your jib is not hoisted all the way either.

[Bully]

Originally Posted by Don C L

We had another thread on this topic not too long ago. I'll see if I can find it. In the mean time those lines are called jack lines and they are there to help keep the sail managed when you put in the first reef. It allows you to furl the main without it being all bunched up at he mast. Your main, if it truly is hoisted all the way up, must be the wrong size for the boat. I suspect something is holding it up from being fully hoisted though. Can you look up to the head when it is hoisted with binoculars and see if it is all the way up, or does it stop somewhere close to the top?

By the way your jib is not hoisted all the way either.

Exactly, and one small point. I recently had a client with similar.
When I went on boat, it was his boom vang being on tight that stop sail going to full hoist???

[shrspeedblade]

Are you able to loosen that down haul line for the reef points at the luff? From the picture that appears to be inhibiting good tension on the luff from what I can tell.

Do you have good luff tension with the 1st reef in?

[Don C L]

By the way, the vang and the mainsheet need to be released before hoisting the main too. It looks in the photo like the vang is holding the boom down.

[mhinnc]

Thanks for the replies. I'm not at the boat right now. I'll use the binoculars to see that it is to the top. Knowing the jack line name and what they're for helps.

FYI, re the jib, that was put up temporarily last time out briefly in November while the genoa is getting some tlc. (I like my 135 - putting it on after winter.) The jib wants to cause the top of the furler to bind so it requires a slack halyard to fully unfurl and I hadn't yet pulled up the halyard. I appreciate the advice on the vang. In this photo, I did pull it tight to try to eliminate some of the lapover at the boom.

It may simply be the luff is too long for the mast.

[Don C L]

Originally Posted by mhinnc

It may simply be the luff is too long for the mast.

Oh, is that main new? Or off another boat?

[Bowdrie]

Originally Posted by mhinnc

It may simply be the luff is too long for the mast.

I think a couple of posts alluded to it, but is the sail a "real" sail for a C&C 30?
Would a sailmaker put-on the C&C emblem if he made a replacement sail?
Might not be of any concern, but in the pictures/diagrams of mast/mainsail we always see the boom precisely at a right angle to the mast.
In real life this is not as common as one may think.

[mhinnc]

Originally Posted by shrspeedblade

Are you able to loosen that down haul line for the reef points at the luff? From the picture that appears to be inhibiting good tension on the luff from what I can tell.

Do you have good luff tension with the 1st reef in?

When I'm back at the boat in a week or so I'll double check, but I'm thinking there was good tension with the 1st reef in.

[JBP]

You can get more slugs and attach them easily enough. SailRite has them.

If the halyard is tight, could it be the sail is high as it can go?

[JBP]

Also you could rig a Cunningham is the lowest reinforced grommet and use that to pull down the sail. The bottom foot or so would be effectively unused, but it should get your sail shape much better.

[Knotical]

Agree with others-

1. loosen everything (mainsheet, vang, outhaul, lazy jacks) before you pull the halyard up
2. use cunningham to flatten the lower sail
3. if it is a new sail and the issue bothers you have it re-cut

The lower part of jib is also pretty loose..

[GordMay]

Originally Posted by JBP

Also you could rig a Cunningham is the lowest reinforced grommet and use that to pull down the sail. The bottom foot or so would be effectively unused, but it should get your sail shape much better.

Mainsail Controls:
The Cunningham [Tack Downhaul] is used to tension the luff of the mainsail, removing puckers [crow's feet] along the luff, and to move the draft forward, offsetting the wind’s efforts to push the draft aft. Most mainsails come standard with a Cunningham cringle, on the luff, above the tack. This way you can rig a purchase system to the cringle, to add tension to the luff of the sail, especially in light to moderate winds.

See the:
MAINSAIL TRIM GUIDE ➥ https://www.quantumsails.com/getatta...nsail.pdf.aspx

And:
➥ https://nauticedsailingschool.com/le...nsail-controls

[mhinnc]

I don't know how long it's been on the boat, as we've only had it about 2 1/2 years. No doubt past its prime, but able to help get the boat up to hull speed in the right conditions.


This sail shape issue has only been noticed late in this past season, so something with the rigging must have been inadvertently changed to cause it. Until we decide if a new(er) boat is in the offing this sail will have to suffice.


All the good advice is much appreciated! Thanks especially GordMay for the diagram and links.

[tenchiki]

I think the jackline needs to be tightened to bring the sail closer to the mast. One end of the jackline should have a knot that can be adjusted. If this is a new sail, the sailmaker will usually leave the jackline slack to be adjusted on installation.


Also, it sounds like you got a loose-footed main, it is supposed to "droop" over the boom some. In the picture, you may have the outhaul too tight, there needs to be some shape in sail.