March 30, 2012
Here's a shot of a Presto 30 mainsail in production on our loft floor. I've laid a batten along the luff to show just how much luff curve there is in these sails.
And here's the same sail as represented in Sail Pack:
Luff curve is one way that we add shape to an otherwise flat sail, but we also use luff curve to match mast bend. If there isn't enough luff curve for a mast then you get ugly wrinkles extending from the clew to the middle of the mast as the sail distorts to fit the spar.
A Presto 30 mast is an unstayed, carbon tube and very straight. However, it changes dramatically as the wind picks up, bending to leeward and opening up the leech. Trimming the mainsheet tensions the leech and bends the mast even more. Too little luff curve and the sail quickly turns itself inside out. So . . . a curvy sail for a bendy mast.
Check out Thorfinn Expeditions and the Presto 30 in action here:
March 14, 2012
Traditional sails? We can do that. This is the foresail we are making for Portland Schooner Company's schooner Wendameen. Although it looks somewhat like a modern square-head mainsail, this gaff-rigged foresail is actually quite different. Gaff rigged sails evolved as a way to carry more sail area on a short mast. A shorter mast is stronger and less complex than a longer mast and given that schooners were mostly working craft, stronger and simpler was a good thing. Although a gaff-rigged schooner doesn't go to weather as well as more modern boats with Bermuda rig mainsails, they reach and run quite well with all that extra sail area.