Question on weather helm and sails

[tom ricks]

Last year my wife very nicely bought me a brand-new, expensive mainsail for my Typhoon.

I didn't get a new jib or genny, though. I wonder if having a tight main and a floppy foresail might have increased weather helm. If so, what might I do about that, aside from buying new sails?

Thanks,
Tom Ricks
Deer Isle, ME

[moctrams]

Have her "pop" for a new jenny. Just tell her sails come in pairs.

[Gary H]

You may not need a new Genny. A few years back, I replaced a 35 year old main sail on my Typhoon with a brand new main. For the first few months, I found i could not control the boat as well as I had with the old main. I had learned to sail with a blown out main and now had to learn to adjust a bit differently.

My Ty had a traveller which helped as I could let it out to lee a bit. Also, you may want to reef a little sooner than you would have with your old sail. I can't say I ever experienced weather helm on the Ty but I could get overpowered with a full main.

While the balance of fore and aft forces is the major factor in weather helm, angle of heel is also a factor.
A powerful genny may not decrease weather helm as it also increases the angle of heel. At least that has been my experience.

[Bill Goldsmith]

There are many factors that could result in a big difference between the old main and the new one. My experience on my 27 was that the new main decreased weather helm. The old main was bellied out and ineffiicent, and I was constantly battling the tiller. The new main was an instant fix. In your situation, it's possible your old main was barely adding to the boat's drive, and with the new one, you are noticing the center of effort has moved aft.

Try adjusting your forestay and backstay to move your mast forward in small increments. You want some weather helm, and the boat was designed for it. Tilting the mast forward in very small increments should give you noticeable results. Then make sure the whole rig is tuned well. Brion Toss has a really good video on this, and there are YouTube videos as well showing you how to do this without relying on a rigger.

[Joe Myerson]

There are many factors that could result in a big difference between the old main and the new one. My experience on my 27 was that the new main decreased weather helm. The old main was bellied out and ineffiicent, and I was constantly battling the tiller. The new main was an instant fix. In your situation, it's possible your old main was barely adding to the boat's drive, and with the new one, you are noticing the center of effort has moved aft.

I had a similar experience when I replaced the original mainsail that came with Creme Brulee.

[steveg]

A new main should help quite a bit with weather helm. It is not because the center of effort moves aft, if my understanding is correct. In a new crisp main the deepest point of the draft remains more stable, somewhere around one third of the sail width from the mast. Imagine an airplane wing, the thickest point is near the front edge of the wing and does not move. In an older sail which does not hold its shape very well the draft moves toward the stern, thus causing the boat to head up more than it would if it remained stable (where it is supposed to be). If the lateral force on the boat moves aft the bow will head in the opposite direction. In an older "bagged out" sail the draft tends to move aft in general and more so in puffs. Older sails do not hold their shape as well due to the quality of the fabric degrading due to wear and uv damage, the sewing and seams may also stretch out some. It is my understanding that is why on the old time sailing ships they saved their best sails for when the wind was strongest, and used their worn sails in light air when they would take abuse from flapping. The tendency to head up is what we think of with weather helm. A new genoa would not hurt, but would not have as great of an effect on reducing weather helm. New sails naturally will perform better than older sails. This is why serious racers get new sails frequently, at least if they wish to be competitive. Hopefully this is an adequate explanation, although I am no sailmaker.

[tom ricks]

Thanks--that helps, and makes me better understand how the boat behaved last summer.
Best,
Tom Ricks

[gates_cliff]

Thanks for the information on weather helm and old sails.

I've been trying to compensate for the strong weather helm on Katie Girl, to no avail. Messed around a little with rigging, just a little for fear of really screwing things up. Always adjusting the traveler and never could really get it resolved so maybe I can convince my wife to buy me a new mainsail! Now that is a really knee slapper! She thinks I spend way too much money on my boat now, and I feel I don't spend nearly enough!

[Megunticook]

Interesting knowledge. I have a Ty Senior with a fairly new main and the original working jib plus 2 newer Gennys, so will be experimenting with all that. Never sailed the boat, just went through the sails with a sailmaker.

[Uffda]

Which sailmaker did you use ?

[Megunticook]

Gambell and Hunter in Camden. We spent probably close to an hour going through the 5 sails that came with the boat when I bought it in October.

[Gary H]

On my 22D, I have a middle-age full batten main. While I have only recently begun to sail this boat, there is more weather helm - with full sail over 12 knots - than I would hope. I have been giving some thought to the battens.
The sail seems to take the shape of the battens with the deepest bend being mid sail. I am thinking of converting to tapered battens which are thicker, and harder to bend, as you go aft. I expect that this may move the center of effort forward and possibly play a role in decreasing weather helm. Any thoughts or experience with this?

[steveg]

Hi Gary,

Have you tried reefing the main? If so how does that effect the weather helm? I have old sails and need to reef early to reduce the weather helm. Normally I reef right around 12 mph of wind speed. Others here have reported not needing to reef as early with a new main in good condition. It seem that if the sail is stretched out due to degradation of the material or from sailing in too much wind that stiffer battens would not correct the problem. Have you tried increasing the outhaul tension and the halyard or downhaul tension? The maximum draft of the sail should not be in the middle of the sail. It should be in the first third of the sail width if I am not mistaken.

[gates_cliff]

Just to add, my weather helm is present even when reefed.

[steveg]

Hi Cliff,

What size jib are you using? Having a big enough headsail often balances out the weather helm. My experience has been that if the head sail is too small the main will tend to overpower it causing the boat to head into the wind. I reef the main before I use a smaller headsail. Do you experience too much helm in 5 - 10 mph of wind? Do you tune the mast yourself? Others have described taking up tension on the forestay and easing the backstay causing the mast to move forward a little which also helps to reduce the helm. I have not needed to use that technique as the helm can be balanced by sail selection and trim. You do need some weather helm so the boat heads into the wind in moderate wind, but it should not be overpowering. In a large gust or with quite a bit more sail than is necessary there will be a strong tendency to head into the wind.

The prior owner of my boat advised he had a weather helm problem. He also told me he almost never used the big genoa, a 155, and almost always used a working jib, a 110. I have used the 155 almost exclusively with wind under 15 mph. When the wind gets much above 10 reef the main and it balances out the helm. If I use the working jib it is almost always with a reefed main, and more wind, unless I am just trying to ghost around. There is another fairly recent post discussing mast rake where Maine Buzzard describes adjusting the mast to reduce weather helm. It is good information.

When I tune the mast in the spring, around here you launch every spring and haul out in the fall. I start with the mast approximately vertical. I determine this visually from a little way off to the side of the boat. You can use a plumb bob and see how the mast lines up with the string. From there you try to get the top of the mast centered on the boat, using the boom topping lift as it is in the center of the mast. The distance from the top of the mast to each upper chainplate needs to be the same. Then take up the tension on the forward lowers and slightly less on the aft lowers. The uppers should be pretty snug but not bar tight. The lowers should not be as tight as the uppers. At this point look up the mast track with your eye along the track. It should be straight. If you are not sure apply some additional tension to one of the uppers by pulling on it while you look up the track and see what happens. This should either cause it to straighten some or curve more.

The manual provides with respect to tension, "Headstay and backstays should never be taken up so tightly that they will not give an inch or so if you pull on them with moderate force. Upper shrouds should also be tightened equally and have about an inch of give to them. Forward lower shrouds should have one to two inches of give and the aft lowers slightly more. Under no circumstances take up the rigging to bar tight tension. Both the mast and the boat can be severely damaged by excessive tension."

With this set up when you are in a bit of wind the middle of the mast will move forward which puts tension on the windward aft lowers. The leeward stays will not have much tension on them at that point. Go sailing and see how it feels. You really can not hurt the rig by adjusting the rig, unless you put far too much tension on the whole thing or you release entirely the forestay or backstay and the rig falls over. If you are still having a helm problem at this point I would consider easing the tension on the uppers and lowers slightly to give you some slack and take up on the forestay and ease up the backstay to move the masthead toward the bow of the boat. Then retighten as described above and then go sailing and see how it feels. When sailing look up the mast track. It should be straight, without the top of the mast hooking to either side. If there is a curve in the track, toward either side, the tension needs to be adjusted so the track is straight.

When you are adjusting the tension be sure to hold the top of the turnbuckle with your hand or a wrench so it does not spin when you rotate the turnbuckle body. This insures that the threads are drawn into or eased equally.

Hopefully, if this process is greatly in error someone else will chime in. It has worked well for me.