C&C 27 Association Forum

Hugh Morrin,
I have no experience with a kevlar fiber sail on a C+C 27 but I have plenty of experience with Kevlar reinforced sails on larger boats. C+C 40. Sydney 42, etc. In addition I am an applcation engineer for power transmission belts that use kevlar as a reinforcing member. Here is the skinny on Kevlar.
It's total elongation over it's lifetime is less than 1%. In addition Kevlar has no elastic properties. Once the fibers ar elongated the deformation is permanent. Therefore there is no "elasticity" of the sail. Kevlar does not shrink nor does it elongate under a wide temperature range. -30 F to 190 F. That is why it is used on Vbelt drives for heavy industrial machines.
Therefore, I would guess that if the sailmaker is giving you an honest opinion that the sail is changing luff lengths over its lifetime then he has to be refferring to the fabric portion of the sail, not the reinforceing members. If that being the case they made a sail out of strong material and glued it together incorrectly not taking advantage of the strength of the reinforcing fibers.
My experience with plastic go fast sails is that they look they same the first day you set them, every day you set them until UV takes out the fabric and you end up with the luff, leach and foot of the sail with noting in between. (Rather cool to see a main sail explode in 30 knot breeze. Noting left but the batten pockets hanging from the leach. Race 4 Chicago Noods. And we told the owner to put the dacron main up that day at the dock).
Once you get a good plastic sail, you can slightly alter the depth with lots of mast bend for the main and halyard tension for the jib, but only so much. You can mover the draft position a limited amount with luff tensions so that is why you have to get the thing made correctly from the get go.
Finally I raced on a 1967 ish Red Line (CAl) 30 many moons ago. We got a plastic hgeadsail for the boat. In the long run a big mistake due to the fact that you can not bend the rig that much. We selected the rating at 22 knots top end for the sail. We never liked the way the thing set until one day we were racing with 20 apparent. Man did that sail look great and we were so much faster than the competitors that had been kicking our buts up to that point in time.
Therefore what did you tell the sailmaker other than make one just liek this?
Did you specify depth, draft position and wind rating? I think he either got it wrong or you haven't seen the sail under all of the possible conditions.
Good Luck.
Eric Steele