After having my roller furling drum replaced (from a profurl to a harken mkiv) and adding garhauer ez genoa car controls on my 39' foot 2006 beneteau sailboat, I am experiencing sail trim problems with my classic (not furling) mainsail and my furling 140 genoa. I suspect my rig needs adjusting, but don't see the specific problem I am having coverered anywhere. 1. Unable to get the draft to be consistent thru the mainsail. Towards the bottom of the mainsail, the draft is very far forward, at about 15%. Changing the outhaul, the vang position, nor playing with the mainsheet halyard tension moves it past 20% and then causes other problems in the sail plan. Meanwhile the draft in the middle of the mainsail can get as far back as 60% and the top of the mainsail, as back as 90-100%, for example in 5-8 knots of wind. Changing the genoa halyard tension dosn't help enough either. 2. The correct position for the jib cars has now moved very far forward (to get all the tell tales to rise/fall together), by more than 2 feet from the previous position. At this forward car position the draft in the genoa is very deep, the top of the sail is closed, and otherwise looks dreadful. I go faster on a close reach at this position then any other position, but it looks wrong. If I move the car where I use to have it, the wind just spills off the top half of the genoa. 3. Also on the mainsail, for example last week on a reach in 8 knots of wind, I noticed some wrikles radiating seperatly from both the tack and the clew. Each had five or more wrinkles radiating 1/2 way towards the center of the sail before they stopped. Neither tightening or loosing the outhaul had any effect, neither did changing vang or main halyard position, nor loosing the genoa halyard. Any ideas ?
Sail trim problems
- Thread starter b393capt
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Holy Cow !!
I'm having a very difficult time trying to imagine a main sail with draft at 15% at the foot 60% in the middle and 90% at the top ALL at the same time. Something is VERY seriously wrong with that picture! Can you post a picture of your main in this circumstance with the pertinent data so we can comment on what might be the problem? Dan, after posting I realized that you're in the next harbor east of me. If you want to take a ride over to Oyster Bay some time maybe we could meet up and I could have a look see for myself.
I'm having a very difficult time trying to imagine a main sail with draft at 15% at the foot 60% in the middle and 90% at the top ALL at the same time. Something is VERY seriously wrong with that picture! Can you post a picture of your main in this circumstance with the pertinent data so we can comment on what might be the problem? Dan, after posting I realized that you're in the next harbor east of me. If you want to take a ride over to Oyster Bay some time maybe we could meet up and I could have a look see for myself.
- Jan 22, 2008
- 519
I'm no expert here but
When I put all of your 'sypmtoms' for each sail together, they seem to match a conditon where the forestay is too tight. Is there any chance that when you added your furler, the forestay was shortend to accommodate your furler, but shortened too much? The solution, if you can, is to back off the tension on the forestay, and increase tension on the shrouds and backstay to compensate. On a boat this size you may want to use a Loos guage to ensure the proper tension in your rigging. You don't mention any change to boat handling or pressure on the helm, assuming you have a tiller. If the center of effort has moved forward the helm should feel lighter, or more balanced, or weather helm may be non existant. In a worse situation, you may have lee helm, but you would likely have noticed this and mentioned it in your post. Let us know what you find out.
When I put all of your 'sypmtoms' for each sail together, they seem to match a conditon where the forestay is too tight. Is there any chance that when you added your furler, the forestay was shortend to accommodate your furler, but shortened too much? The solution, if you can, is to back off the tension on the forestay, and increase tension on the shrouds and backstay to compensate. On a boat this size you may want to use a Loos guage to ensure the proper tension in your rigging. You don't mention any change to boat handling or pressure on the helm, assuming you have a tiller. If the center of effort has moved forward the helm should feel lighter, or more balanced, or weather helm may be non existant. In a worse situation, you may have lee helm, but you would likely have noticed this and mentioned it in your post. Let us know what you find out.
Are you using a GPS to calibrate your speed?
While you adjust the sails do you use a GPS or knotmeter to gauge your speed? If you are using a knotmeter it could already be somewhat fouled. I like to have both a knotmeter and a GPS to help determine if certain adjustments to the sails are helping or hurting my way. I keep a Lightning sailboat rigged for racing over at my sister's house on Lloyd Neck and launch from Lloyd Harbor. We could both sail around to Cold Spring Harbor or Bayville (I think that is where Alan keeps his boat), and he could help us both be better sailors! Actually your problem sounds like it could be that your outhaul is not working and the wire has gotten stuck on its sheave inside the boom. If you can't get the mainsail to flatten out more than you are reporting then this is my vote for the likely culprit. I would also go out with you on your boat and try to inspect your issues with you as I am in the area quite frequently and also own a 27' Tartan that is up the Hudson at Nyack, NY. I am aspiring to become a marine surveyor and am taking a course in marine investigations currently. I also ask for no fee even if I can help you. We are all always learning when it comes to sailboats.
While you adjust the sails do you use a GPS or knotmeter to gauge your speed? If you are using a knotmeter it could already be somewhat fouled. I like to have both a knotmeter and a GPS to help determine if certain adjustments to the sails are helping or hurting my way. I keep a Lightning sailboat rigged for racing over at my sister's house on Lloyd Neck and launch from Lloyd Harbor. We could both sail around to Cold Spring Harbor or Bayville (I think that is where Alan keeps his boat), and he could help us both be better sailors! Actually your problem sounds like it could be that your outhaul is not working and the wire has gotten stuck on its sheave inside the boom. If you can't get the mainsail to flatten out more than you are reporting then this is my vote for the likely culprit. I would also go out with you on your boat and try to inspect your issues with you as I am in the area quite frequently and also own a 27' Tartan that is up the Hudson at Nyack, NY. I am aspiring to become a marine surveyor and am taking a course in marine investigations currently. I also ask for no fee even if I can help you. We are all always learning when it comes to sailboats.
Questions Answered
1) Not sure it's worth mentioning. After the furler was added I had tremendous weather helm (e.g. 12-20% rudder to compensate in 12 knots of wind) , we then realized that the shrouds were way to loose, and the yard took care of it. What is worth mentioning, is that compared to before the furler change, before I had some weather especially at 12-15 knots before reefing, now I can get the weather helm less than 4% in most circumstances under 15 knots, and have sometimes measured a lee helm up to 2% of rudder, which was correct with a move of the traveller which already seemed to be in the correct position. To give numbers, I would have to say my weather helm before was in the 6-12% range before, and now it's in the -1 % to 5% range, in conditions ranging from 5 to 15 knots. The higher number in the range being the amount in higher wind or being less careful about balancing the boat, and the lower number in the range being what I can get if I am careful balancing the boat under 10 nots of wind. 2) Visually the tack of the sail appears to be higher than it was before. Would seem that's not possible if the forestay was shortened. 3) My speed is measured by an airmar ultrasonic speed sensor that was calibrated to GPS at slack tide. After a few months experience, seeing the numbers side by side on my chartplotter with the GPS and being aware of the currents, I think it's pretty good. I have a boat speed display at the companionway so it's easy to see the effect of sail trim 4) Outhaul functions properly. Has 3:1 rigging, and moves smoothly especially in 10 knots or less of wind. Can observe the draft changes easily as the outhaul is adjusted, but most of the effect goes to the middle and top of the sail. 5) Perhaps we can go on a sail. Let see what other advice comes up on this thread. Also the yard is going on a sail with me Monday to investigate, and I can post there thoughts here as well. I am still hoping someone looks at this info, and knows the answer.
1) Not sure it's worth mentioning. After the furler was added I had tremendous weather helm (e.g. 12-20% rudder to compensate in 12 knots of wind) , we then realized that the shrouds were way to loose, and the yard took care of it. What is worth mentioning, is that compared to before the furler change, before I had some weather especially at 12-15 knots before reefing, now I can get the weather helm less than 4% in most circumstances under 15 knots, and have sometimes measured a lee helm up to 2% of rudder, which was correct with a move of the traveller which already seemed to be in the correct position. To give numbers, I would have to say my weather helm before was in the 6-12% range before, and now it's in the -1 % to 5% range, in conditions ranging from 5 to 15 knots. The higher number in the range being the amount in higher wind or being less careful about balancing the boat, and the lower number in the range being what I can get if I am careful balancing the boat under 10 nots of wind. 2) Visually the tack of the sail appears to be higher than it was before. Would seem that's not possible if the forestay was shortened. 3) My speed is measured by an airmar ultrasonic speed sensor that was calibrated to GPS at slack tide. After a few months experience, seeing the numbers side by side on my chartplotter with the GPS and being aware of the currents, I think it's pretty good. I have a boat speed display at the companionway so it's easy to see the effect of sail trim 4) Outhaul functions properly. Has 3:1 rigging, and moves smoothly especially in 10 knots or less of wind. Can observe the draft changes easily as the outhaul is adjusted, but most of the effect goes to the middle and top of the sail. 5) Perhaps we can go on a sail. Let see what other advice comes up on this thread. Also the yard is going on a sail with me Monday to investigate, and I can post there thoughts here as well. I am still hoping someone looks at this info, and knows the answer.
Help ?
Does these symptoms match to a solution ? Wish I could post a diagram, to show how bad it is.
Does these symptoms match to a solution ? Wish I could post a diagram, to show how bad it is.
Problems
B393capt: If it were me and my boat I would do 2 things. First I would take Alan up on his offer to look at your problem. Have him drive his car to your boat and buy him lunch and see what he can figure out. If he can't figure out a cure perhaps he would suggest secondly that you need either a rigger or a sailmaker or both. On your weather helm, you are OK at 1 to 5 degrees. It should not be necessary to move jib fairleads over 2'. Adjusting the outhaul causes mainly the bottom 2/3 of the sail to react. If I didn't know better I would say that your situation is upside down and I can't figure it out without seeing it.
B393capt: If it were me and my boat I would do 2 things. First I would take Alan up on his offer to look at your problem. Have him drive his car to your boat and buy him lunch and see what he can figure out. If he can't figure out a cure perhaps he would suggest secondly that you need either a rigger or a sailmaker or both. On your weather helm, you are OK at 1 to 5 degrees. It should not be necessary to move jib fairleads over 2'. Adjusting the outhaul causes mainly the bottom 2/3 of the sail to react. If I didn't know better I would say that your situation is upside down and I can't figure it out without seeing it.
Have diagram
Good advice, I will do that. I have a rough diagram, but no way to send it thru this thread that I can think of. My hotmail email address starts in danielwcorcoran (trying to avoid posting the address exactly so it won't be picked up by spam robots) Dan
Good advice, I will do that. I have a rough diagram, but no way to send it thru this thread that I can think of. My hotmail email address starts in danielwcorcoran (trying to avoid posting the address exactly so it won't be picked up by spam robots) Dan
Does she have a hollow leach?
Pictures are sometime deceiving. It looks like you don't have any roach on the mainsail at all and possibly a hollow leach. A hollow leach (the line from head to clew curves inward toward the rest of the sail) can make the trimming more difficult. The mainsheet will tighten up the leach first and leave the rest of the aft end of the sail loose. It tends to cause the wrinkles coming from the clew also for the same reasons. Basically you can't use the sheet to pull down on the sail because the leach tightens up first and takes all the tension.
Pictures are sometime deceiving. It looks like you don't have any roach on the mainsail at all and possibly a hollow leach. A hollow leach (the line from head to clew curves inward toward the rest of the sail) can make the trimming more difficult. The mainsheet will tighten up the leach first and leave the rest of the aft end of the sail loose. It tends to cause the wrinkles coming from the clew also for the same reasons. Basically you can't use the sheet to pull down on the sail because the leach tightens up first and takes all the tension.
Could be the angle of the photo but....
I don't agree with the location of the draft at the lower batten. I agree with the location of the draft in the top of the main at the top three green dots, but it looks to me to be further aft than your green dots in the lower section. Which means that the situation isn't as bad as you were describing. One thing you might want to play with is your batten tension. On full batten mains, the batten tension can change the location of the draft. It also depends on what kind of battens (how stiff) you are using. We use a stiffer batten for heavier air and a softer one for lighter air. On some boats like the ID35, they set and re-set the batten tension prior to each race. It is, for them, a sail control that they use regularly. Might be worth a try.
I don't agree with the location of the draft at the lower batten. I agree with the location of the draft in the top of the main at the top three green dots, but it looks to me to be further aft than your green dots in the lower section. Which means that the situation isn't as bad as you were describing. One thing you might want to play with is your batten tension. On full batten mains, the batten tension can change the location of the draft. It also depends on what kind of battens (how stiff) you are using. We use a stiffer batten for heavier air and a softer one for lighter air. On some boats like the ID35, they set and re-set the batten tension prior to each race. It is, for them, a sail control that they use regularly. Might be worth a try.
No Roach
Bill- The reason I think that the sail looks like it has no roach is that it is twisted off. The top batten is way open relative to the rest of the sail. It needs to be sheeted in more. That plus the angle of the photo makes it look like it has no roach.
Bill- The reason I think that the sail looks like it has no roach is that it is twisted off. The top batten is way open relative to the rest of the sail. It needs to be sheeted in more. That plus the angle of the photo makes it look like it has no roach.
Info on this photo
I agree it could have been sheeted in some more to reduce twist at the top of the sail, not to much though as I wanted i a bit open given the 2 foot seas and moderate wind, but that wouldn't have helped me move the draft position at the bottom of the sail aft to 50-55% as has been my goal. Imagine, to try to achieve that goal I work with my outhaul (let it out) and halyard (increase first, but also try decrease). As I do that, at best I can move the draft position at the bottom of the sail another 10% aft, but in doing so, the draft in the middle and top of the sail move aft also into something more wacko that this, and no amount of halyard tension can fix the draft position at the top of the sail. I don't have a cunningham or adjustable backstay, nor have I needed one prior to the headsail roller fuller upgrade to get a good sail shape. In regards to the position of the green dots, I do have a higher resolution photo to work from, but even here you can see there are wrinkles at the position of maximum draft (shouldn't be !!) along the whole sail and that the green dots suddenly move in closer to the mast about mid-way thru the sail. In answer to other questions. There is some, but not alot of roach on this mainsail. I am unfamiliar with the term hollow leach, but I think from your description I can say that it does not at the time I took this this photo.
I agree it could have been sheeted in some more to reduce twist at the top of the sail, not to much though as I wanted i a bit open given the 2 foot seas and moderate wind, but that wouldn't have helped me move the draft position at the bottom of the sail aft to 50-55% as has been my goal. Imagine, to try to achieve that goal I work with my outhaul (let it out) and halyard (increase first, but also try decrease). As I do that, at best I can move the draft position at the bottom of the sail another 10% aft, but in doing so, the draft in the middle and top of the sail move aft also into something more wacko that this, and no amount of halyard tension can fix the draft position at the top of the sail. I don't have a cunningham or adjustable backstay, nor have I needed one prior to the headsail roller fuller upgrade to get a good sail shape. In regards to the position of the green dots, I do have a higher resolution photo to work from, but even here you can see there are wrinkles at the position of maximum draft (shouldn't be !!) along the whole sail and that the green dots suddenly move in closer to the mast about mid-way thru the sail. In answer to other questions. There is some, but not alot of roach on this mainsail. I am unfamiliar with the term hollow leach, but I think from your description I can say that it does not at the time I took this this photo.
Wrinkles
I don't know but those wrinkles from the clew could be partially caused by the reefing rig. The lines and the blocks. The lower reef line may actually be a bit tight. I also would have put the three green dots further aft. Probably the one at the bottom where the lazyjack shadow hits the sail or even farther back. As a matter of fact, I'd draw a straight line from the top three on down. So,are your battens tapered in a way that is moving the draft forward?
I don't know but those wrinkles from the clew could be partially caused by the reefing rig. The lines and the blocks. The lower reef line may actually be a bit tight. I also would have put the three green dots further aft. Probably the one at the bottom where the lazyjack shadow hits the sail or even farther back. As a matter of fact, I'd draw a straight line from the top three on down. So,are your battens tapered in a way that is moving the draft forward?
Battens
The battens are not tappered. They are uniform across their length. Also, all four of them are of the same width, type of material, etc. I agree the aft reef line appears tight in this photo, it may very well be, the sail was reefed in it's previous use and the wrinkle that I see there is more pronounced then it usually is. I will endevour to get a better photo, but from dealing with this problem for 2 months, I am sure the reef line isn't an issue and a new photo will be similiar.
The battens are not tappered. They are uniform across their length. Also, all four of them are of the same width, type of material, etc. I agree the aft reef line appears tight in this photo, it may very well be, the sail was reefed in it's previous use and the wrinkle that I see there is more pronounced then it usually is. I will endevour to get a better photo, but from dealing with this problem for 2 months, I am sure the reef line isn't an issue and a new photo will be similiar.
Here's a comment
From "The Sailmaker's apprentice" http://www.mhprofessional.com/product.php?cat=132&isbn=0071376429 He refers to bias elongation in the cloth. (like pulling a handkerchief by it's opposite corners.) Bias Elongation in the clew is the result of unwanted cloth distortion on the bias. You may either have a hardware/reinforcement problem(Outhaul too tight or main halyard too loose) or also could be a cloth problem (ie: a permanent stretch) causing these wrinkles or "girts". From: http://www.amateurboatbuilding.com/articles/howto/lugsail/lugsail.html Keep in mind that this link is not for a sloop main but for a different type of sail. near the bottom: "Here is some advice about how much to tension the tack line. It varies with wind strength. Look at the sail as you do it. See Figure 6. As you tension the sail with the force of the wind in the sail, stress folds called girts will appear in the sail. If the girt runs from throat to clew you need more tension. If the girt runs from head to tack you either have it right or can reduce the tension. A perfect setting will have no girts. Usually at the initial setup I put in a good girt from peak to tack. Then I watch it while sailing to see if that girt disappears. Then when convenient I trim as required. Remember that changing sailing conditions will change the tension requirements." I need to read this one a few times: http://www.northsails.dk/uk/main.asp
From "The Sailmaker's apprentice" http://www.mhprofessional.com/product.php?cat=132&isbn=0071376429 He refers to bias elongation in the cloth. (like pulling a handkerchief by it's opposite corners.) Bias Elongation in the clew is the result of unwanted cloth distortion on the bias. You may either have a hardware/reinforcement problem(Outhaul too tight or main halyard too loose) or also could be a cloth problem (ie: a permanent stretch) causing these wrinkles or "girts". From: http://www.amateurboatbuilding.com/articles/howto/lugsail/lugsail.html Keep in mind that this link is not for a sloop main but for a different type of sail. near the bottom: "Here is some advice about how much to tension the tack line. It varies with wind strength. Look at the sail as you do it. See Figure 6. As you tension the sail with the force of the wind in the sail, stress folds called girts will appear in the sail. If the girt runs from throat to clew you need more tension. If the girt runs from head to tack you either have it right or can reduce the tension. A perfect setting will have no girts. Usually at the initial setup I put in a good girt from peak to tack. Then I watch it while sailing to see if that girt disappears. Then when convenient I trim as required. Remember that changing sailing conditions will change the tension requirements." I need to read this one a few times: http://www.northsails.dk/uk/main.asp
I was going to say the same thing......
The wrinkles coming off the clew look like stretch and the reefing line, while snug, don't look like they are tight enough to be causing any of these wrinkles. I also still don't see the draft like you see it and because the leech is so open at the top, I think that it is hard to get a good picture of the problem. Is there any way to get a better picture of the sail sheeted in with the battens parallel to the boom? The best angle for this picture would be from under the center of the boom.
The wrinkles coming off the clew look like stretch and the reefing line, while snug, don't look like they are tight enough to be causing any of these wrinkles. I also still don't see the draft like you see it and because the leech is so open at the top, I think that it is hard to get a good picture of the problem. Is there any way to get a better picture of the sail sheeted in with the battens parallel to the boom? The best angle for this picture would be from under the center of the boom.
More pictures to be taken
I can see how you could disagree with my placement of the green dots on the bottom of the sail in this picture, although I think I was generous with the green dots on top by not placing them even more aft then I did. In any event, I only took the one set of pictures thinking it was unlikely the draft position would be visable at all. Now that I see it's workable to see the draft of a white sail with my camera, I will get some better shots. I could also get a picture of my best attempt to move the draft of the mainsail draft position to 50%, althought that's just going to be an ugly picture, maybe it will add to the discussion. Look back here in about 5 days for more pic's.
I can see how you could disagree with my placement of the green dots on the bottom of the sail in this picture, although I think I was generous with the green dots on top by not placing them even more aft then I did. In any event, I only took the one set of pictures thinking it was unlikely the draft position would be visable at all. Now that I see it's workable to see the draft of a white sail with my camera, I will get some better shots. I could also get a picture of my best attempt to move the draft of the mainsail draft position to 50%, althought that's just going to be an ugly picture, maybe it will add to the discussion. Look back here in about 5 days for more pic's.
Did you mess with your topping lift?
If you inadvertantly changed the topping lift height to hold the boom up when doing your modifications the vang could not get the leech tight enough because the topping lift would prevent any more downward action for the boom. From the picture, it simply looks like the vang needs to tighten up the leach and the outhaul needs to be loosened. If you've tried this and it didn't work, did you then check how tight the topping lift was?
If you inadvertantly changed the topping lift height to hold the boom up when doing your modifications the vang could not get the leech tight enough because the topping lift would prevent any more downward action for the boom. From the picture, it simply looks like the vang needs to tighten up the leach and the outhaul needs to be loosened. If you've tried this and it didn't work, did you then check how tight the topping lift was?
Topping Lift
Did I mess with ... Yes, the topping lift is set to prevent the boom from hitting the bimini. In this picture the topping lift appears to be so loose it's flopping in the wind. In the picture from back to foward, is the half of the split back stay, the topping lift, and the 2nd reef line.
Did I mess with ... Yes, the topping lift is set to prevent the boom from hitting the bimini. In this picture the topping lift appears to be so loose it's flopping in the wind. In the picture from back to foward, is the half of the split back stay, the topping lift, and the 2nd reef line.
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