Calvert Sails

Rig
At time of launch our rig comprised:
Mainsail 726 sq ft 67m2.. Jib (self tacking) 280 sq ft 26m2. . Screecher 702 sq ft 65m2. Storm Jib 150 sq ft 14m2
We had increased the area of the rig (jib plus main) from the 78m2 suggested by Derek to 93m2 .

The Main, Jib and Screecher were supplied by Calvert Sails of Florida and were constructed using his ‘Load Path’ method with taffeta backing cloth overlaid with mylar tapes. The mylar tapes are about 10cm wide, reinforced with carbon and kevlar threads, are sticky backed and are stuck to one side of the taffeta, so reinforcing the the sail along the main load bearing lines. The sails are a heavy construction, at the upper end or weight for cruising multihull sails and were sold to us on the understanding that they would be ‘good for a circumnavigation’.
In the Canaries we bought a 2nd hand spinnaker and in the Carribean an old monohull genoa that we switch with the jib for downwind reaching and running in light to moderate conditions.

Screecher. From before we launched we had concerns about the compression loads the screecher was going to put on the forward beam so we added heavy aluminium reinforcement to our plank (which runs from the foredeck to the beam). The first time we flew the screecher it popped the bowsprit up - our bob stays are at too much of an angle to provide enough down force. So we had a dolphin striker constructed and riveted it to the beam. Next time out the bolt rope pulled out of the top of the sail (the sail maker had used the wrong thimble) and we had to wait till arriving in Cork to get it fixed as the cloth was too heavy for the local sail maker to work with. At this stage I was having grave concerns about the sail, it was so heavy it took three of us to mount or dismount it and the loads on the fittings were huge. It wouldn’t set upwind, am not sure if this was because it was cut too full or if it was because I was just not willing to put sufficient load on the halyard (for fear of breaking something) to tension the luff enough. We had 3 days good days of downwind sailing with it from Cork to Spain and then a few hours with it on and off crossing the Atlantic. However as we approached the Carribean the bowsprit began to come apart so that was the end of the screecher for us and we were all glad to see the back of it when we shipped it back to Florida. On balance I calculate that the extra performance we got the sail was more than outweighed by the speed we lost from the extra weight of the sail, plank reinforcement and the bowsprit !
Jib. The jib never set too well when close hauled. Although self-tacking (we have a jib track on the foredeck), when close hauled the sail gets caught on the mast spreaders so it has to be released and re-sheeted. This actually makes for more sail handling when beating upwind than with a normal jib or genoa. I now realise that a small jib is a poor choice for a cruising multihull (you need a foresail that can be easily reefed and set as conditions vary).
Main. In Spain we had a problem with the intermediate cars pulling the eyelets out of the sail. We took it ashore and had repairs made and the ties changed. We also had problems with specified battens breaking even in light conditions that took a long time to resolve. Eventually we replaced the top polyester batten with a much stronger epoxy one and since then it has been OK. The main was cut with significant curve in the luff (our mast has 15 cm of bend in it to accomodate the sail shape). I am not convinced that the performance improvement we get from this is justified for a cruising boat given the extra stress on the mast and the additional load on the halyard to raise our already heavy sail.

Seperation problems. In Tonga we noticed we were getting some separation (I use the word separation because the tapes were glued to the taffeta rather than laminated) of the mylar tapes on the jib. By New Zealand the separation was spreading rapidly to about 10% of the sail area of both the jib and the main and some of the tapes were breaking. At this stage we had only sailed with the jib for about 30% of the trip (some 5000nm), the rest of the time we had been using the genoa or spinnaker (so roughly about 1/6 of a full circumnavigation). At Calverts request we took the sails to a local sailmaker. His view was that the tapes were losing their adhesion because of the UV and his advice was just to continue using the sail (on the taffeta layer) until it wore out. Calvert asked us to take it to another sailmaker which we did, he also thought the problem was from UV but was willing to repair the damage to the tapes under advice from Calvert. We eventually reached an agreement with Calvert Sails that they would provide new tapes and pay for the repair (we were outside the guarantee period of 1 year). We also had the option to return the sails to Florida for reconditioning but although we had 4 months up on the hard it had taken so long to get any agreement that there was insufficient time to have this done. Once the repair was undertaken they refused to pay the bill and 4 months later I am out of pocket for the repairs.
All the professionals I have spoke to thought that the separation was because the tapes were exposed to UV and that this type of construction was unsuited to cruising sails. Calvert’s view was that it could have been caused by the sails lying folded for some time before use, however the pattern of damage to the sails -worst around the high load areas (clew, luff and leech) - doesn’t support this arguement.