Curling TriSpi

[PaulP]

I put a new set of sails of TriSpi40 on my boat. Within just a few weeks, the leech of both sails displayed curling. The sails had not be exposed to any high winds or luffing. Figured it was just a bad cut, so I put on another set. That set also displays curling on the leech.

Is this a characteristic of TriSpi? Does anyone know why this occurs? The material has been stored on the shipping roll, approx 3" dia. The curls are slight, probably a 3/4" radius on the last 3/4" of the sails.

They have not been exposed to high heat or mis-handled in anyway.

Can anyone shed any light on what might be going on and any ideas on how it could be corrected.

Thanks

Paul

[kahle67]

First of all, are you building these sails yourself?

Reichard

[PegLeg]

Paul

Almost any of the mylar based materials will exhibit a "curl" in the direction of the core winding. It seems to be greater, the closer the material is to the core it is wound and stored on.

My past experience has been with the curl at the foot which is less damaging to performance than a leach curl. However neither is acceptable in my opinion. Aparently; whomever made your two suits rotated the cloth 90 deg to get rid of the foot curl only to get the leach curl instead.

The conventional "fix" that is usually offered is to wind the sail on a roll of some type in the opposite direction to the existing curl. Let it stay that way for at least a month or more; all the while praying, to whichever diety suits you, for a blessing and curl removal. With all that done, un roll the sails, wait a few days and you will find the original curl has returned.

Should you try to use heat, you do so at great peril. Anything hotter than what you can wash your hands in will result in validating the chaos theory beyond a doubt.

If they were my sails I'd end them back for credit and look to a new sailmaker to make a set that does not curl up like a window shade. Either that or have a very strong conversation with the current sailmaker about what you expect to receive when the current sails are returned to him.

Yes, there are sailmakers who do know how to cope with the material and furnish minimal curl sails. There are different methods used by different sailmakers to reinforce the leach against the "curley scourge". and at least 1 loft knows how to produce good sails by "cloth selection" from the outer(larger diameter) layers of the manufacturing roll.

While I am at it, I have to ask what is so darn sacred about TriSpi??? I have often wondered why most of the other classes use straight drafting mylar, taped together with not a stich to be seen. I have a set and I must say that they are quite competitive (more so than the skipper) in anything over 3 kts. It did take me a while to learn how to use and care for them but I would, given a reasonable choice, never go back to TriSpi.

Good luck

[PaulP]

The sails were built by me, so I am the culprit. This is the second set that displays the problem. I did cut the panels from the "inner end" of the roll but I find that unlikely as the cause. Other sails I have built did not display the problem. This is my second 100' roll of trispi so I have successfully built a number of sails.

Refering to the jib, it is five panels. All five were cut from the roll with the same grain direction, 90 degrees from the leech. Yet the lower panel curls one direction and the upper four panels curl the other direction.

I feel it has something to do with the assembled sail. Other pieces I've cut lay flat after being stored for over a year. Tensioning the leech tends to accentuate the curl due to the extra fabric in the roach which overhangs the tension line from clew to head.

If it matters, the scrim in the material runs horizontal/vertical and is parallel/perpendicular to the waterline (approx).

From what I've seen and experienced, I don't believe it is due to abuse of the sails.

I am hoping some sailmakers will join the discussion on the use and handling of trispi.

[RMDJBD]

PAUL

EVERY SET OF SAILS I HAVE IN TRISPI ARE DUING THE SAME. I JUST LIVE WITH THE PROBLEM. HAD A NEW SET STRAIGHT OUT OF THE BOX AND ON THE FIRST TIME OUT THEY HAD THE "LEACH FLIP". THE ONLY THING I WAS GOING TO DUE, BEFORE I GOT BUSY, WAS TO TAKE A SET TO MY "NORTH SAIL LOFT" AND MAYBE THEY CAN TELL ME WHAT IS GOING ON.

THE ONLY OTHER THING I WAS GOING TO DO WAS TO SCOLUP THE LEACH TO REMOVE SOME OF THE FLIP, BUT I THINK THAT IS AGAINST THE RULES. IF IT IS NOT AGAINST THE RULES LET ME KNOW.

Bob Dudinsky

[kahle67]

Make sure you are aligning your upper panel templates across the roll of material and not down it. You can rotate the bottom panel to keep the foot from curling. Some sailmakers switch from one side of the material to the other as you move from one panel down to the next. I have made a bunch of sails myself but came to realize that it's more than a bitch to get them right. One less thing to worry about when left to the pro's.

I did get my hands on a roll of 40 one time that would not relax no matter what. This might be the case in your situation.

Good luck, Paul.


Reichard

[bodacious]

Guys... Having fought with this problem I know where you are coming from ! I believe that the problem is in the manufacturing process of the material itself! Ther is not a whole lot you can do "after the fact" Since the material is a laminate and is rolled as it comes off the "press" the roll or curl you are finding is actually cured into the cloth. The closer to the core or start of the roll , the more severe the curl. Every set of sails that I have seen (or made ) from mylar laminate has a bit of curl.... no matter WHO made them! Drafting mylar is a great substitute... very easy to cut and tape but very fragile ! The woven polyesters like "Icarex" and "Toray" are really great materials.... great for light air sails and strong enough for almost any wind conditions if assembled properly! I have a set of Light air "A"s that are very promising as I learn to tune them and I have also made a couple of "B" rig Jibs that are "bullet proof" .These where built from Icarex which is a .6 OZ material. Hell, you don't even need a hot knife if you use a VERY sharp razor to cut the stuff. The polycarbonate resin used in the cloth is that strong! Just food for though! DougB

[s vernon]

Sailed/Raced with Stater yesterday at Murphey Candler Park in Atlanta. Great to see him. As usual he gave me a lesson 12 to 2. He also gave me a care package of TriSpi 40 sails that he was about to throw out. There are some nice sails, but they have been rolled on tubes and stored in a storage room in Atlanta for a few years. They developed some foot curl in that time.

I reverse rolled them and stuck them in the hottest part of the attic for just a few hours and they all got good and flat. I had to put extra reverse bend in the corner patches by hand to get them flat. This heat wave is good for something anyway.

Chris is racing F16 cats these days, but (after some encouragement) he threatened to show up at the Valentine regatta which, is almost local for him, with the old Ozeemun submarine. I hope his schedule permits it.

Scott

[Fred Maurer]

I have used a strip of "blue" tape along the foot of both the jib and the main to hold the curl at bay. It works as long as the strip is wide enough to convince the sail to behave. Further, it does not seem to inhibit the set of the camber on either tack. The only trick is in using care when applying the tape. Good news, blue tape can be removed from the sail with equal care.

[Jim Hale]

As someone who makes his own sails from TriSpi 40, I too have experienced the dreaded "foot curl." I have successfully removed it by dragging the foot of the sail over a sharp edge, inducing a reverse curl, much as one would try to curl a sheet of paper. The sharper the edge, and the more times one does this, the greater the effect. End result is a flat foot. (Did I really say that?) Oh, yes, the sails need to be removed from the rig.

Jim Hale
USA 2056