Status update....  after much noodling on the computer, designing, drafting, and hand wringing I committed to sewing the foresail (smaller than the main) first and conside it a learning experience....  the girlfriend, knowing me well, said that I would not be happy with the first sail so just get that over with.  The cloth was ordered and received (Weathermax 80), needles, thread (V92), seam stick, webbing, velcro, and the all important seam ripper...  Then we converted the living room and dining room area into a sail sewing area...  all ready to go and no more excuses.  I started in late November.  

The sail has an 8% camber, about 38 square meters, an AR of 2.6 and nominal batten length of 4100 mm.  P is 1400, plan formis similar to David's Weaverbird and was discussed here.  I opted for creating the camber using broad seams - actually these are the vertical seams that I used to build each panel. I used a "shelf" angled at 30 degrees.  The 3D shape was done in SketchUp and I also exported out the 2D pannels.  Then I used QCAD to add seam allowances, draft any extra pieces like reinforcements, batten pockets, and padding.  Since I had so many pieces, I opted to have a sailmaker draw all of them on the cloth and I cut them out with a hot knife.  After carefully nesting all the pieces based on the order I would need them for sewing and how they best minimized cloth wastage.  The final lines - cutting, seam allowance, reference marks, and some identification on each piece were done on a 10 meter table and I brought home six roles of canvas with mystery lines on them.

I have two sheets of plywood on the floor for a 1.2 x 5 meter work surface onto which I can pin and use my hot knife.  I also expanded my dining room table with plywood to have a 1.2 x 3.6 meter work table.  The sewing machine - Bernina 217 with a servo motor, knee lift and reverse foot petal - has been a joy to work with.  It is not a walking foot or needle feed machine.  Turns out 1/2 of the sail will fit in the throat.  

Some random thoughts...  

• Seam stick - double sided tape specific for canvas and used to hold pieces together before sewing - is great. The cloth seems to selfclean the needle. On a different sewing project I had to constantly use alcohol to clean the needle/thread.
  
• The cloth is pretty stretchy, so when pinning it down it is important to stretch a bit because both the seam stick and the cloth on top will be stretched when they are applied and the idea is to match everything so it all "jumps" back to neutral when the pins are removed.  
• Alignment marks - all longer pieces had marks to help me find the middle of a piece or where a curve started. Because of the cloth is relatively stretchy, these really help.  It was helpful to start sticking thinks together from the middle and work outward.  I also used marks to show where to attach batten pockets, padding, and reinforcements.
• V92 thread requires many bobbin changes and starting new bobbins mid-seam.  V69 would have made it all a little easier.  
• I used a 5x5mm zig-zag stitch with two rows of stitch on a 20mm seam allowance.  Smaller zig-zag but with a similar stitch length would have used less thread per seam and extended the bobbin.  
• I had issues with puckering of the seams that I was not able to resolve.  

Currently I am attaching luff tape/webbing, then the webbing for the battens. I am intensely nervous about the final sail, which given space limitations, it is all mystery until the darn thing is hoisted...   More to come.

As always, thanks to everyone in this group for their advice and encouragement, but esp Arne and David - the former who was most generous hosting us in Norway and taking us for a sail and feeding us hot chocolate and waffles.  And David for sharing his vast experience.

e&e

My intention for my rig is to use 12mil thick, 50mil wide neoprene rubber strips to cushion the battens, so they don't clap against the mast. This stuff is readily available, not terribly expensive, and can be ordered online. Neoprene is very good for absorbing vibrations and sound as well, so it should perform well.


I haven't done this YET, but I was a sound engineer back in the day, and we used neoprene for some applications in sound and vibration insulation. My guess is it would work very well, or at least as well as anything else one might use.


EDIT: I realized I didn't mention.. this sort of rubber is a bit sticky, so you would have to sheathe it over with a thin, slick covering like sheet vinyl, or alternatively a bit of canvas or poly cloth.

Paul Thompson wrote:

If you fill your hollow aluminium or steel mast with polystyrene balls ("beanbag balls") you support the masthead wiring conduit and you eliminate any ringing noises.

But you still get a hard 'thwack' rather than a soft 'thump'.  It depends how noise gets to one as to whether it's an issue.  We can't all turn off our hearing aids!!!

Two things with PVC pipe worth mentioning:

1. when you cut it, you end up with very sharp edges which need carefully rounding over so that they don't cut into the sail cloth
2. PVC is hard and therefore noisy against a tin mast.
   

Batten pockets and bumper between the batten and the mast....

Of the different design options, my current preferred one is the "split PVC pipe" mentioned by Paul in an earlier post that simply clips over the batten pocket onto the batten.  For 50mm diameter battens the same size PVC (for our sail grey PVC or black ABS since it coordinates better with our burgundy sails)  seems to work perfect.  Some narrow strips of foam insulation, used to seal windows, stuck onto the ID of the split pipe create a little more "give" and shock absorption.  Friction between the batten and mast is very low.  Finally, there is no extra sewing or gap in the in the batten pocket or attaching padding to the batten.  

Question - how long should these be.  On my 4100mm long battens and 15% overlap, I have 600mm in front of the mast line.  Is 200mm or so on each side of the mast, i.e. total length of 400 to 500mm sufficient?

e