Annie,
I don’t think we should make a rule on which mast rake is the “right” one. Forward rake surely works, and I have seen it on Samson’s foremast for years. Plumb masts work as well, and even those with a bit aft rake, which I had on my dinghy Broremann. My “rule” is; when in doubt, look up how the Chinese  did it: On the 3-masted Hong Kong schooners, all the foremasts had plenty of forward rake, the main masts were mostly about plumb, and many of the mizzen masts had some oft rake in them. My guess is that they had practical reasons for this  -  for instance to increase the gap between the sails, to avoid sheet tangle. Nowadays, my default mast angle is perfectly plumb, if there is room for it. I find it easier to step and unstep plumb masts, and also to climb them.

David,
I would think that your chosen sailcloth is good. On the 20sqm sail of  my Frøken Sørensen, the Odyssey cloth is just a bit on the heavy side for “inflating” the  cambered panels properly, in the lightest winds. With a hinged batten sail, this is not an issue. (.. I guess the bagginess in the fore section of your sail will be fairly moderate...) As for the risk of the hinges nipping holes in the sail, I never had problems with that on Malena’s sail. My guess is that the bit of tension I kept in the sail along the battens was enough to prevent the hinges from chewing on the cloth.

Cheers, Arne

Jerry, 

I know the cloth is rather heavy for Weaverbird, but it's such nice cloth, and the price is so nice, that I couldn't resist it! My battens are going to be quite light, so the total sail bundle should come in at a tolerable weight.

With either of the amateur panel seaming methods, that is, with the edges of the panels ending up facing either to starboard or to port (I'm going to use the latter, as the batten is closer to the sail), I've found absolutely no issues with the strength of the thread. For that first run of straight stitching that joins the panels and carries the load, I can't see any chafing issues, so V92 could be used, but equally, V69 will be strong enough. For the second, backup line of stitching, too, there isn't much of a chafing issue. There's more of an issue when you seam two or more cloths vertically to form a panel, and then the topping lifts can attack the stitches, over time. There, I'd agree with using V69 if it beds down better.

Try to avoid sharp edges on the hinge components, and opening and closing gaps that can nip the sail. I'd certainly put a patch of cloth under the hinge, and there may be an argument for a piece of sailmakers soft leather, for long distance use, but the damage is often done some way away from the hinge, when reefed.  I seem to recall that some people have made tubular sheaths of cloth to enclose the hinge, which would protect the sail under all conditions. These sheaths probably have to be regarded as expendable, but would be easy enough to make and replace.

David, I'm in the process of hot knife cutting the Clipper Canvas panels for my Rustler 31 sail, and agree that it's lovely stuff to work with.

As I understand it the version we've bought is 7.2 oz 'Clipper Light' which equates to approx 300 gsm in metric terms or 9 oz in the UK ounces per square yard measurement. PJR suggests much lighter cloth weights (table 5 on page 166) for a given sail area, but your use of Clipper Canvas for Weaverbird's modest sized sail clearly departs from this. Any thoughts?

Also now you've seen the cloth would you use V69 or is the heavier V92 bonded thread a better match? My first sewing attempts on some scrap show the V69 beds into the cloth better than the V92 and theoretically should be less prone to chafe, but is it strong enough for joining the panels/batten pockets using Arne's amateur methods?

I'll also be using jointed battens but am wondering what reinforcement/chafe protection is needed where the joints rub against the sailcloth.

I'm now gathering materials and doing some more work on the design.

The tapered mast tube, 9.2m x 165mm dia x 3mm wall, is on order with the Aluminium Lighting Company, and I'm awaiting a delivery date.

I've received 30 running metres (51 sq m) of the tan Clipper Canvas. It's beautifully soft, yet stable, and should make a great junk sail. The only thing amiss is that it hasn't had its edges trimmed, it's as it came from the loom with loose weft threads at the edge. That means I'll have to hot-knife them using a straight edge.

I've received a bundle of GRP tubes for the yard and battens. I've chosen 30mm x 27mm for the battens, but I've also bought a length of 38mm x 34mm in case the top batten needs to be stiffer. (I've also bought an extra 3m length of 38mm x 34mm with a yuloh in mind - I'm not at all sure I can live with an outboard as auxiliary, and this boat is small enough for me to try a yuloh).

I've uploaded some drawings here. You'll see that I'm staying with the hinged battens that I was using on Tystie, but with this important difference - the hinge elements are conical, so that there is no tendency to seek any particular orientation about their axes. This was found to be essential to avoid misbehaviour. On Tystie, I tried leaving the (flat) sail unattached to the forward part of the batten, and this resulted in a very desirable cross section to the sail on starboard tack, with the after part of the sail flat, which I consider greatly to be wished, and all the camber in the forward part of the sail. On port tack it didn't look quite so good, as there was a little slackness horizontally in the sail, resulting in vertical creases. 

Now, if the forward part of the sail is attached to the battens, and is not flat but has some built-in camber, then we have the situation that we're familiar with - some curve developing on both tacks, albeit with some disruption by the mast. The amount of fullness needed in the panels has been very substantially reduced by adding in the hinges. This means that there is less disruption caused by the mast than is usually the case with cambered panels and no hinges. The convexity on the edges of the panels is so slight, in fact, that there's no need for shelf feet/broad seams/tucks, a simple barrel cut is that's needed.

My Brother-in-Law has a lathe, and has turned me the double cones and the pattern to make a mould for the outer section (more on that later).

I'll be making each panel from two cloths laid parallel to the leech. This will be the most economical cut, and the after cloth will be a simple parallelogram; all the barrel cut shaping is confined to the forward cloth.

The hinge angle will decrease progressively in the top two battens, and the yard will be a simple straight GRP tube 80mm x 76mm.

I'll be using upper and lower sheets.

So that's the way I'm heading. Of course, having made hinges, I'm halfway to another wing sail... But not in the short term, perhaps. I'd better prove the hinges in a more conventional junk sail, and then think some more about wing sails next winter.

We are also looking at Weatherguard 80, which we are considering as material for our F40. It is  8oz  per yard and 60 inchest wide..  It's weave makes it softer than Odyssey IIII.  Both sides are the same, which may make laying out the panels easier. Because it is not coated, I would consider using a hot knife to cut it, which would help keep the edges from fraying.  It is stretchy on the bias but seems to spring back.  I am guessing that the coated fabrics are stiffer in the beginning, but once the coating breaks down they are the same or worse based on what I've been told.  Yes, no super fun colors (we're still deciding), reds are advertised as fading easier, should dry easier than Odyssey or Topgun when doused so possibly less mold issues.  Costs $11-15/yard in the US depending on color.

Erik