Hi Bill
The AR=2.00 version looks good to me. I would only suggest two little adjustments:

• ·         Raise the whole sail a little so the tack end of the boom clears any guardrail.
• ·         Increase the halyard drift (distance from the 55% slingpoint to the masthead) a little. These days I make this drift 18% of the batten length, B. Some of this distance will be eaten up by the added yard and the blocks, but starting with these 18% will still result in a useful drift.

As for use of top notch sailcloth, it’s your money, so do what you like. Just remember that the load in the cloth of a junksail is just a fraction of that in a western sail of the same size. Diagonal stiffness is not required at all. As long as the canvas is resistant against chafe, rot and sunrot, it will be fine. But the edge of the sail, in particular the leech, must be stiff and strong, either by adding some sort of boltrope, or by fitting stout tabling.

Good luck!
Arne

I purchased this boat about 3 years ago during lockdown in auckland to convert to Jr after we sold our 42ft steel boat we sailed back from Mexico. I finally managed to si ngle hand it down to dunedin in the far south last March April.

Unfortunately I'm not allowed new boat projects till I've built our new house, so the Jr is 1.5 yrs off.

So I've drawn up a sailplan using Arnes design criteria and am offering it up for  comment. I'm thinking I'll use the 45 deg. Shelf foot method as I wood like to use top notch 9 fabric which I think will need to come from US. Shelf ft because of lack of stretch. Mast will be birdsmouth recycled canadian oregon beams .

Hope my drawing is not to confusing, slight distortion from smartphone camera. I've overplayed a 1.9 and a 2 aspect ratio plan. Will probably use AR 2 as will reduce risk of excessive weather helm which I have now(old sails).

Comments welcome

Bill