When designing a sloop sailplan, I like to find the ratio between the mean chord of the sail and the waterline of the actual boat. This gives me an idea on how hard she will be to steer downwind. On my Johanna, the ratio was 0.84 and on my present boat, Ingeborg, it is 0.80. On Johanna I could run out of rudder if I pushed too hard, but the rig pressure and speed of the boat was indicating that I should reef anyway. On Ingeborg, her rudder is so big and efficient that I will reef to save the rig rather than to help steering, so in neither case have I felt any need to swing the sail forward. I still think I will keep this ratio on 0.80 or lower unless the boat is fitted with a particularly big and efficient rudder (..or one plans to swing the sail forward  when reaching and running...)

Pol’s Cornish Pilot has a chord-to-waterline ratio of 0.75. The rudder looks quite big, so I think the boat can be pushed to her hullspeed (6.6kts) on a reach or run before complaining.

Arne

PS: The numbers I have used above are useful for low-balance sails like my Johanna-style sails. On a high-balance sail, and in particular the Split JR, the actual CP will sit closer to the mast, even with the sail stalled, so my hunch is that these sails produce the least weather helm when going downwind. Reports from users of Split JRs support this view.

POL BERGIUS wrote:

Arne's photo shows that the hoseclip method can also look fairly unobtrusive and of course it is quick to take off if needed. Arne, that parrel looks pretty tight to the mast or short. Having just looked at the lovely pics of Footprints and her long batten parrels it makes me wonder: I'd like to be have the option to swing my sail across when right off the wind if better balance is needed, but will that be OK with the Johanna style sail as opposed to Footprints' Fantail type of sail plan?

Thanks for the info on the tape Bryan. I'm going to investigate the self-amalgamating tape in the meantime. Our forward end pockets can be made "just not so tight" so that we can slip them out complete with tape, or should the pockets be fairly precisely the same fit all the way along?!

Pol

Pol,
the Johanna style sail with its 10degrees boom rise could well be modified to be swung forward, as on the photo below. Personally I would not bother. I think that would just be making the construction of the sail (..and the handling of it...) more complicated than necessary. However, I do recommend making the fore batten pockets a bit roomier. This would both let you pad the battens at the mast and let you fit those permanent batten parrels fastenings.

Arne

David Thatcher wrote:

I don't quite know why people are not showing any interest in the studs screwed into the batten to hold the parrels. 

David, I've seen your photo of this system on Footprints and it does look neat. Clearly it works, too, and has stood the test of time and oceans. I may still use the method, though as you can tell I'm quite keen on a "soft" alternative if one can be made to work. My worries about corrosion are obviously un-founded, though something like Simsons as Annie suggests can't do any harm.

Arne's photo shows that the hoseclip method can also look fairly unobtrusive and of course it is quick to take off if needed. Arne, that parrel looks pretty tight to the mast or short. Having just looked at the lovely pics of Footprints and her long batten parrels it makes me wonder: I'd like to be have the option to swing my sail across when right off the wind if better balance is needed, but will that be OK with the Johanna style sail as opposed to Footprints' Fantail type of sail plan?

Thanks for the info on the tape Bryan. I'm going to investigate the self-amalgamating tape in the meantime. Our forward end pockets can be made "just not so tight" so that we can slip them out complete with tape, or should the pockets be fairly precisely the same fit all the way along?!

Pol

ps I need to look again in the Help page for how to paste in part of a previous post neat and tidy with a blue background as others do ;)

David Thatcher wrote: I don't quite know why people are not showing any interest in the studs screwed into the batten to hold the parrels.

David, I think when people are new to junk rig and making their very first sail, they are worried about drilling holes in the battens only to find they are in the wrong place.  So certainly in the short term, they want a different solution.  But photos of your arrangement would, I'm sure, be appreciated.

BTW, I've found that if you coat your stainless steel fastenings with a little Simson's Marine Glue, as they call it here, you don't seem to get corrosion problems.  It's a silicone-free goop, and more forgiving than 5200 or Sikaflex.

POL BERGIUS wrote:

Bryan, just Googled self-amalgamating tape. Looks like useful stuff! Very much like Arne's suggestion  but maybe stickier?! 

I've got some of that heavily waxed flat stuff, Annie, and on our un-anodized battens (even though they may be painted) a combo of tape and that sounds like belt and braces - or even supenders!

Pol.

I don't quite know why people are not showing any interest in the studs screwed into the batten to hold the parrels. This has been used successfully by David Tyler over countless thousands of miles of ocean sailing, and Footprints for 5,000 miles plus of ocean and coastal sailing without any issues, complete success!. It is a neat and tidy, and elegant solution which works remarkably well, takes about 5 minutes per stud to manufacture and install, and if you have a small amount of 12mm thick plastic lying around the only cost is the 8 or 10 guage stainless steels screws used to screw the studs onto the battens. There is no slipping, no wear on the sail, and even looks professional, and the battens do not break even with 2 small holes drilled in them. Even on my old sail with timber battens  I used screws to locate the batten parrels as I could see that was the simplest way to locate them without the parrels sliding along the batten. From memory I had  stainless panhead  screw with a washer on the top and bottom  edges of the batten, and the parrels then tied around the batten and located by the protruding screws.

I will take a photo next time I am out sailing.