A recent article in Sailing World Magazine (September 2001) "Are you ready for carbon-fiber sails?" has stopped short in addressing the unique construction requirements of these sails and comparison to other manufacturer's premium aramid sailcloth. The first time Bob Curry (VP sales for Sabre Sails) saw a new carbon main and jib on an F-31was during a Corsair Regatta in California. He noticed that the clew ring had a lot of rust around it and there was rust leaking from the headboard. What gives???

What gives is electrolysis. The carbon sails are nothing but a big battery conducting a charge through out the sail. This is nothing new. Manufactures of carbon masts and boats are all too familiar with electrolysis and the corrosion of metal fittings when they are not insulated properly from the carbon.

When we asked the carbon cloth manufactures what manufacturing areas need to be addressed and what are their recommendations. They did not know or understand the problems when working with carbon. We also checked with other sailmakers that have made carbon sails and to our surprise they were not aware of a problem either. In other words, a new product has been developed and manufacturing techniques were not addressed.

Who looses in this case?, the customer. The customer gets a very expensive sail and within a month the sail hardware starts to rust. If you must have carbon sails, we recommend that you question your sailmaker on his manufacturing techniques to assure the sail hardware is properly insulated. We had to develop new insulating techniques to isolate the carbon from the hardware.

Another issue is the impact flutter stretch test. We had Dimension Polyant's GPL7 and GPL14 Graphx Carbon tested against 9-K, 14-K DPI aramid sailcloth and Sabre Sails' Super K2 SK09, and SK14. The test was conducted duplicating the test performed by Haarstick Sails. Strips of the Carbon and the both types of Aramid were tested (GPL7 vs 9-K and SK09 and GPL14 vs 14-K and SK14). The strips were fluttered at 30mph against a destructive edge and then stretched after the flutter.

As with any dry inserted yarn, there was crimp associated with running the insertion up and over formed scrims with fill yarns. Low load numbers for the warp are nothing special and while the higher load properties of the carbon look good, the initial crimp prevents the warp 1% figures from living up to their potential. Fill performance was quite good with both styles having a fill 1% over 100lbs.

STYLE	WEIGHT oz.	WARP 10#	200#	1%	Fill 1%
GPL 07	5.04	1.9	12.6	328	110
9-K	3.90	0.6	10.9	305	65
SK09	4.24	1.3*	12.5*	277*	114*
GPL 14	5.54	1.6	10.5	390	110
K-14	4.90	0.4	8.2	401	85
SK14	5.05	1.5*	10.1*	365*	112*
*SK09 and SK14 results show fill performance, the primary fabric direction for comparison to the warp (primary direction) of the other styles. SK warp numbers are compared to the fill numbers of the other styles. Weight is shown in oz. / sailmaker's yard. Lighter is better Warp 10# and 200# smaller number is better 1% and Fill 1% Larger number is better Summary: Carbon is on average 10% to 20% heavier than aramid for similar high load stretch numbers. Carbon has on average 3 to 4 times more stretch at low load (10#) compared to aramid due to crimp. Carbon has on average 15% to 20% more stretch at high load (200#) compared to aramid.         And Carbon is on the average 25% to 46% more expensive than comparable aramid styles.

Will carbon be appropriate for sailcloth in the future? Perhaps. Obviously it is not the "silver bullet" the recent article made it appear to be. As always, an educated consumer is a happier consumer. Caveat emptor.