The Johanna-style sails I use have just about vertical leech, which prevents the battens or boom from catching fur sheets. I just have to extend batten 2 from top, as shown on Fig 4 of this write-up. I do that to all the Johanna-style sails, and I make that batten twice as strong as the lower ones. On later boats, I also take care to fit the aft batten ends flush with the leech.

As for camber through twist, with the Johanna-style sail well reefed, it becomes a fanned sail, and adds a bit camber through twist, as shown below. These sails set and pull surprisingly well with only 2  -  4 panels set.

Arne

 

PS: I think it is a good idea to hang on to Fantail's original sail for a while to learn more, before deciding for a new sail.

Hi Arne

In the brief time I've had Fantail her sail has developed new tears, and I've been busy with the palm and thread. The cloth in the stressed areas of the sail is remarkably weak - a small child could push a finger through it. (Luckily, Fantail has had one lady owner, who only sailed to church on Sundays). While I don't think the sail is in any mortal danger, its days are numbered and this is what's driving the 'what's next?' considerations .

I can't possibly comment on the merits of the different sail types but with everyone's help I've addressed most of the issues in what I've got: stresses in the throat area, the difficulty  of peaking the yard, high loads in the top sheeted batten. You were absolutely on the money with the suggestion of changing the sling point on the yard, and everything has flowed from that. I don't think there's any problem specific to the design of the sail. The sheeting is something to look at in a new sail. So I think the new sail options are wide open.

I've been amazed - astounded - at how well Fantail goes to windward in a blow, in a rough sea, well reefed, and with a lousy set. With four panels up and one of those scalloped shut, Fantail will happily trot to windward on a close reach. Given that the sail looked like a sack of potatoes at the time, it's hard not to conclude that a real sack of spuds will drive a decent hull to windward in a blow almost as well as the most finely crafted sail.

Thanks for the write-up link! Still learning...

Bryan

Graham Cox wrote:

Bryan Tuffnell wrote:

Thanks for the advice, everyone. Fantail's sail will be up for replacement in the near future. Arne's shape, HM or another fantail?

Arne's sail is, of course, basically an HM sail, but the transitional panel is a great improvement on the original, especially for a cambered sail, though I'd incorporate it in a flat sail too.  That would win my vote.  Also, another interesting question, what material will you build it out of?  My new sail is 7oz Dacron, but I recently visited Michael and Wendy Willett on their catamaran, Crusader, and looked at their split-junk sail built from the material that used to be called Mustang.  It has been sitting in the sun for two years and looks as good as new.  mehitabel's sail is built from Topgun and is in perfect condition after 10 years in the sun (no sailcovers on either of these sails).  I kind of regret I did not go down that route.  (Also, there's Weathermax 80 and Clipper Canvas to consider).  So many choices and so few sails!

A factor for Fantail when considering low AR sails is sheeting angle. She's a small bird. I find she has a tendency for the upper sheet span to snag on the lower batten when gybing and occasionally when tacking. A length of hose may be an inelegant solution but it seems preferable to give some thought to the angle and position of the leach.

I'm too fresh to this to have an opinion but right now I tend towards getting some camber through twist. A factor is simply location: here we get a combination of onshore wind and practically unlimited fetch. Unlike being offshore, some genuine windward performance is useful and I have a feeling that too much camber in the panels detracts from an adavantage of the junk when the sails empty and fill in swells. I'd be interested in others' opinions.

It's all ponderings for the future. Fantail's sail is not in great shape but with care she'll hang in a while longer while I learn more about her.

Bryan Tuffnell wrote:

Thanks for the advice, everyone. Fantail's sail will be up for replacement in the near future. Arne's shape, HM or another fantail?

Arne's sail is, of course, basically an HM sail, but the transitional panel is a great improvement on the original, especially for a cambered sail, though I'd incorporate it in a flat sail too.  That would win my vote.  Also, another interesting question, what material will you build it out of?  My new sail is 7oz Dacron, but I recently visited Michael and Wendy Willett on their catamaran, Crusader, and looked at their split-junk sail built from the material that used to be called Mustang.  It has been sitting in the sun for two years and looks as good as new.  mehitabel's sail is built from Topgun and is in perfect condition after 10 years in the sun (no sailcovers on either of these sails).  I kind of regret I did not go down that route.  (Also, there's Weathermax 80 and Clipper Canvas to consider).  So many choices and so few sails!

Annie Hill wrote:

... a Prusik knot ... it's a hitch, not a knot ...

Elegant way for this is to weave a long enough Turk's Head grommet to fit the 3-doubled-passes, last one cow-hitched, around the spar. The flat lay of the Turk's Head gives a good slip-resisting contact surface, sometimes needed with the modern synthetics.

Not everyone has the time or patience to play with traditional seamanship rigging, so a quick work-around that still does the same job is to strip the cover from a piece of (relatively large-diameter) serviceable scrap double-braid and tie it into a properly sized grommet. Flat braid (i.e. sail tie) does this well also.

The resulting core should be saved as it is a nice solid-braid, prefect for lashing lanyards, &c. I have salvaged long lengths of core from otherwise sun-deteriorated lines (discarding the cover). Getting the cover off is an exercise in understand the physics of the Chinese Finger Trap.

My penchant for refraining from discarding things suggests that even the sun-frazzled covers can serve a an oakum substitute, with a bit of tarring. (This thought probably needs a slap-down).

Peace all, Michael 

Annie Hill wrote:

Paul Thompson wrote:

It set well enough when Annie was sailing her, so presumably you have changed things? May be you should check with Annie again.

Oracle, you are too kind.  I ended up with one permanent crease because I couldn't bring myself to force it out.  What I want in SibLim is a sail like yours - the foresail, if my memory serves - that hangs without a crease even when the luff-hauling parrel isn't set up. 

Hi Grasshopper, yes it's the foresail that hangs as you say. However once you sheet it you do need to put a small amount of tension on the LHP/THP (to counter act the downward pull of the sheets).

The main is also setting quite well now... the trick was to move the standing part of the halyard to an attachment point 10% of the yard length aft of the sling point. Now the tension on the sheet not longer pulls the leach down and the THP has become redundant. Splitting the mainsheet into two parts has further reduced the downward tension created by the sheets.