e36 main sail leech

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Sep 19, 2004
85
Hunter e36 Vancouver
I have a 2012 e36 that I am going through a shakedown to get issues figured out.

Even with the boom all the way down, the main sail leech is still not tight and has a built in twist to it. When reefed, the clew rises further up and the twist is even worse. Generally have to move traveller up beyond midpoint to counter the twist.

I initially thought that the mast may have had too much rake preventing the boom from dropping further down.

The dealer said there is no rake to the mast set up and suggested that the main sail may have to be trimmed.

We finally had a sail maker looked at the situation last week.

He thought that the mast top is a bit further back than he would expect. When the main sail is pulled completely out and pulled flat, there is only a slight amount of twist to the sail. However, when the outhaul is let out a bit to allow the main to form a belly to get more lift in light airs, the clew moved up with the reduced tension of the outhaul and the twist increases.

The sail maker said this is the way it is with furling mains as it is not possible to build in too much curve in the main without wrinkling it in the furling process.

There is the possibility of putting a strap from the clew to the boom to limit the clew from rising when the clew is loosen to form a draft in the sail but this will increase drag in furling. I don't think that will work anyway as the clew rises quite a lot when the sail gets furled in.

He further said there is no point trimming the bottom of the main as the clew will rise when trying to form a draft on the main.

He suggested loosening the vang and let the boom move up a bit to form a more gentle twist.

The sail actually looked better with the loosen vang but it does not make any sense to me. Loosening the vang means letting the boom rise and let the weight of the boom pull on the main instead of tension from the vang or main sheet. To me, tightening the vang or mainsheet and adjusting the traveller should have the same effect except perhaps it is not an instantaneous adjustment to the sail as the weight of the boom would have with a looser vang or main sheet.

I had a 2004 H33 before this and I was able to tighten the leech by lowering the boom even with a draft on the main.

Comparing pictures of my H33 with the way it is now with the e36, the clew on the 33 is much lower than the e36 when the sail is all furled in the mast.

It seems a very low probability to me that the main sail dimension would be wrong for a prodcution boat like this so I am hesitant on insisting a trim to the main sail but that seems the logical thing to do.

I keep thinking that there is something else missing here.

Any ideas?

Thanks.

Oliver.
 
Feb 17, 2008
144
Hunter 36 Kristiansund N, Norway
How is your top telltail in your main? It should be flying backwards as much as possible (90% of the time should be possible) and then the twist it right. It is not unnormal to keep the traveller over the middle to have it ok, but not the sail itself.

Regards
Andreas
 
Feb 26, 2004
23,081
Catalina 34 224 Maple Bay, BC, Canada
I'm having trouble visualizing your comment: "when the outhaul is let out a bit to allow the main to form a belly to get more lift in light airs, the clew moved up with the reduced tension of the outhaul and the twist increases.

If the clew is connected to the outhaul car, how can the clew "rise?"
 
Sep 19, 2004
85
Hunter e36 Vancouver
Stu,

My memory is that the outhaul line starts from the outhaul car, goes through a pulley connected to the clew, then back down to the outhaul car before going down to the end of the boom and come back through the boom, down the mast to the coach roof etc.

When easing the outhaul, the outhaul line tension is reduced, the clew then rises as the lines are at about 45 degrees from the outhaul car to the clew. More sail twists results and in my mind cancelling the extra lift from more sail draft.

But then I just tried to look up a picture of either the e36 or 33 to include here to illustrate my point and I found it a bit different on the picture for the 33 then I imagined on the e36.

I am going to take a picture of it on the e36 tomorrow to post it and also to compare with the arrangement on the 33 to see if it is identical.

Andreas, I am actually getting the two bottom tell tails trailing almost all the time and some times even the top one. So the sail twist created with the boom at the lowest position is likely okay a lot of the time. It just feels funny that there is no more room to move the boom down any more and I keep thinking that there may be some wind condition when I would like less twist than it is now. I have not ever adjusted the main sheet on close reach ever since getting the boat last September. Just trying to have these issues figured out before the warranty expires in a couple of months.

When reefed, I move the boom above the mid point so that I do not have to fall off too much from the wind direction. That means some of the sails, the bottom portion, also is over the midpoint. Otherwise the top part of the main is completely twisted out, flapping and not catching any wind. Also seems to be sacraficing another 5 to 10 degrees off the wind when reefed. So my guess is that if I can lower the boom some more, I will be able to be a bit closer to the wind.

Thank you very much for your ideas, Stu and Andreas. Will post photo tomorrow.

Oliver....
 
Sep 19, 2004
85
Hunter e36 Vancouver
It rained for quite a few days and I didn't get a chance to take pictures.

However, I think I have it figured out.

What is needed is to pull the clew all the way out to form an extremely flat sail before letting the out haul back to creat a draft or belly in the main sail. It seems that when the clew is pulled way out, the tension on the clew forces it down tight to the outhaul car. Thereafter, when the outhaul is eased, the clew stay low and close to the car even when a reasonable draft is formed.

I don't know if this is a characteristic of the furling sail, the car, or the geometry of the outhaul line arrangement but my problem seems to be solved. Just pull it all out before backing the clew. Previously, I would stop pulling when I had the sail shape I wanted.

Hope this is helpful to others who may experience the same issue!

Oliver....
 
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