Cutting sails

Been back in PEI since May 1 getting the boat ready to be put back in the water – bottom paint, a new coat of paint on the hull (schooner black) and rudder repair.

The docks here at Charlottetown yacht club are still being put in which has meant delays for me but I’m now slated for re-immersion this Saturday, 19 May.

I’ve started to work on the sails, using the a vacant room in the yacht club to measure and cut the sails. I’ve purchased a good working domestic sowing machine and hope to get them stitched up next week.

junk sail main

main sail

I’ve modified the design somewhat, taking a foot off the luff/leech and introducing an additional batten into the fan head. This decreases the panel width  which should improve control of the sail shape when under sail. The shorter luff/leech will allow greater clearance between the halyard crane an the yard sling which should reduce tension and allow a more free swing to the sail. I’m guessing the new mainsail size is now reduced by some 20 sq ft down to 430 total. This will in effect move the centre of effort slightly forward. I’m expecting a slightly better performance and working mechanics from the changes – although there’s a lot of guess work involved of course.

junk foresail

foresail

Likewise with the foresail I have introduced another batten into the fan head making it a 3 panel fan. Otherwise the dimensions remain the same – 225 sq ft.

I am considering introducing some camber into the sail by means of curved batten pocket tabs, which appears to be the technique used on the latest sail of the Junk Perigrine – (although when I sent a request for info, in English and German, I received no reply). I’m considering a 9 percent camber (meaning 9 present of the batten length depth of the central battens) – with a 3% and 6% moving up from the boom and down from the yard. My main concern with such an approach is how well it will work when the sail is windward of the battens. I figure each panel will take on an individual camber as opposed to a whole sail camber when the sail is lee of the battens. Of course if it works like shit I’ll simply bring it back to a flat sail with a little extra sowing.

I’m not inclined to follow Arne’s curved panel construction not just because it’s a lot more work in design and construction (and I’m lazy) but also because for long-distance sailing., which is practically all I do, I think the vertical seem design lacks the robustness and long-term durability of the vertical seams in ‘traditional’ junk sails.

It would be great to hear from someone who has experimented with curved batten pocket tabs to introduce sufficient camber into the sail. If it happens that I’m the fist to try this technique – well someone gotta do it!

 

 

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One response to “Cutting sails

  1. Perhaps a design employing deliberate weakening in the batten at the design length from the leading edge to allow a wind-enhanced auto-bending movement in the batten giving you the camber from both sides of the sail.

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