I have a 1987 Ericson 34 MKII and am looking to replace my mainsail. Why would I consider a tri-radial verses a cross cut mainsail? I do not race but the family enjoys going fast. Thanks
Hi, The question of whether to choose a crosscut or a triradial panel design for your new mainsail will be answered when you decide whether to choose a woven dacron or a laminated fabric. Dacron sailcloth is woven with more strength in the fill direction (the short direction across a roll of fabric) and laminated sailcloth, whether it is spectra, polyester or kevlar, is made with the strongest fibers in the warp direction (the direction of the length of the roll of cloth). So a dacron sail has to be made in a crosscut layout, to orient the strength of the fabric with the high loads along the leech. A laminated fabric sail is made in a triradial layout, so the strong fibers of the fabric radiate out of the highly loaded corners of the sail.
In general, a laminated, triradial sail will be a little lighter than a dacron sail and it will keep a flatter, more draft forward shape in strong breezes better than a dacron sail. So a laminated sail will give you better performance in both light air and heavy air conditions. Dacron sails are less expensive than laminated sails and in some ways they are more rugged. However, a well made laminated mainsail will last for several seasons of coastal cruising with little or no maintenance. One objection to laminated sailcloth is that it sometimes attracts mildew growth. Some areas of the country are more conducive to mildew than others. Mildew does not cause any structural degradation of the sailcloth, but it can be pretty ugly. During your decision making process, ask your sailmaker if there is a high probability of an occurrence of mildew in your area, and then you will have to decide if you can live with some discoloration of the fabric in exchange for better sailing performance. Regards, Dan Neri