May, 2004:

There are four new styles of Carbon fabrics available this summer that span the needs of most sailing. They fill in the gaps from Grand Prix to Offshore Cruising.

For the offshore sails Dimension / Polyant Sailcloth has introduced their line of CXG Carbon Cruising Laminates. This is something we have been looking forward to for over a year because of the great durability we’ve seen in the GPL Carbon racing laminates. The CXG fabrics feature flat ribbons of Carbon laminated with a Spectra X-Ply to a mylar film, between layers of Dacron taffeta on the outside. To make the fabric even more robust there is an additional Spectra rip stop fill yarn woven into one side of the Dacron taffeta. This not only makes the fabric more stable, but also adds tremendous tear strength. The taffetas are both coated for UV protection.

Spectra Cruise Laminates have always had a problem with long term "creep", are relatively heavy, and in recent years have become very expensive. The Carbon CXG fabrics offer lighter weight, better shape holding, and are less expensive.

For the mid to upper range racing sail Contender Sailcoth has developed a line of multi axial fabrics for building cross cut sails. Called MAXX they have both a line of Pentex fabrics and a line of Carbon / Twaron blend fabrics. The idea is simple and effective; make a sail using cross cut panels with close to the performance of a tri-radial or membrane sail. A Carbon MAXX sail cost around 20% less than a Carbon tri-radial sail because of the big savings in both material and labor cost. In a tri-radial sail we get 72 to 75% efficiency in cloth usage, in a cross cut sail we get about 93% efficiency. A tri-radial sail has 30 to 40 individual panels to cut out and put together; a cross cut sail for a 40’ boat has 12 to 14.

The Carbon MAXX is an asymmetric fabric made up of Carbon yarns at 90 degrees, 82 degrees, and 70 degrees alternating with Twaron yarns at 90, 82, and 0 degrees. By flipping the front half of the lower luff panels and the head panels you can achieve thread layouts that very closely follow what you would have in a tri-radial sail. In the clew you have threads up the leech and angling into the sail at 82 and 70 degrees, in the tack you have fibers running up the luff and angling into the sail, and at the head you have fibers down the luff, down the leech, and down the center.

Bainbridge International has gotten back into the Carbon market with a new line of "Diax CFG" Carbon Fiber Grid. These fabrics are made for standard tri-radial sails and are the first to offer a fabric with both a Carbon warp and Carbon fill yarns. They are made with all carbon warp yarns, alternating Carbon and Twaron fill yearns, and a Spectra X-Ply. The addition of the Carbon fill yarn adds slightly to the weight but should also add to the durability and performance.

Dimension / Polyant has now added to their substantial line of Carbon race fabrics with the much talked about D4 fabric. This process differs from the others in that all the fiber arrays are individually laid out and laminated for each individual sail. This technology is known as a "membrane" "load path" or "string" sails. The cost is kept down by the fact that final construction is done as a cross cut sail; again saving on the labor and total material used. We currently have our first ones on order and they should be delivered to us in the next couple of weeks. I’ll do a full follow up piece with pictures on the actual construction, and the sails on the boats, next month.

Using the D4 process we design our sails using the same software and shapes that we use in our tri-radial sails. The sails are designed as cross cut sails, generally with 5 horizontal seams, and the offsets for each panel are saved in a file. We send the offset file to Dimension / Polyant and specify the type of fiber we want to use, the fiber density, and the film thickness. The sails can be built using Carbon, Aramid, Vectran, or Pentex. Each panel has the custom fiber array laid down and is laminated with heat and pressure. The panels are then shipped to us for assembly and finishing like any other sail we build.

The advantage is a sail with all the primary yarns following the load paths in the sail. Weight is low because you don’t end up with a lot of fibers in some areas of the sails that aren’t really doing anything. Corner patching and reef points are built into the laminate by having the yarn densities increase as you get into the corners. This adds additional strength and weight savings. The result is a sail with proven shape holding and weight savings; over the next few seasons we will find out how much weight is really saved and how their longevity compares to the proven Carbon paneled sails.