Jeffrey, have a look at this photo album. Photo 5 gives proportions for a pocket for a 32mm dia batten, which you could scale to another size.

Time to start cutting out some fabric!!!

A couple of questions about batten pockets before I get going.

I'm going to be using the D-shaped pockets. I would assume that I will need to add a bit of extra material into the sail to accommodate the thickness of the batten. My thought is to add material 1/2 of the circumference of the batten, or 1/4 of the circumference to the batten edge of each panel

Then make the pocket "strip of material" the with of the other 1/2 of the batten circumference "+hem and a little bit of slop"

Is that the way to do it? I'm having a hard time finding information on this. 

David, we made the pair of sails for Footprints and Tystie from Hayward's Sunwing polyester cloth, which sadly is no longer available. It had UV protection - few regular sailcloths have this, and are not a low cost option if they do. I wouldn't use regular polyester sailcloth (Dacron and Terylene being brand names for the polyester fibre from which sailcloth is woven, not the cloth itself) for a cruising junk sail, unless UV protection was built into it. I would want a softer cloth that is happy to be left uncovered when not actually sailing.

Jeffrey, Weathermax 80 is a good cloth, but is a bit tricky to sew. Topgun 9 would be a good choice. In your position, I'd be looking at  this and this . I've always had good results making sails from second grade cloth, as the flaws are generally cosmetic, not structural.

The bolk heads and mast step are all cut out and will be glued in as soon as wether permits.

Change of topic here

Sail material...

Again; I have a sail plan for 305 ft^2  I plan on extensive cruising and ill be in NZ for extend time.

My experience with cloth materials comes from a background in ultralight backpacking. DCF and sill nylon fall apart after 6 months outside. The only piece of gear that I have had hold up for any amount of time is my pack made from High Density Polyethylene –HDPE) reinforced nylon.  it was a black bag witch I'm sure helped stop UV dammige. The inside of the fabric was coated with silicone witch broke down but the  rest of the material held up very well to wear and tear. It is also cheap. 10$ a yard

I was reading about this wether max 80 and it sounds like a good fit for me. Looks like I can get it about 15$ a yard. Not cheap but not too bad. 

Sunbrella- too expensive

Top gun-too heavy

Top notch 9 ??? 

I'm thinking I'll just end up with Dacron. Unless y'all think that there is a material that would last longer that is equal or less in price.

Jeffrey wrote:

David!

Thanks for clarifying. I believe I understand what you are saying ,but I drew a picture to help make sure of it. (Figure 1) I also drew a picture of my original idea just to help clear up any confusion.(figure 2). I would still like to keep a gap in between the keel and the underside of the mast steep but if you think this is not an option I can reconsider the showering with my my head out of the forward hatch. Now here in Chicago, it is hard to get my hands on any hardwood and I don't have any mill to turn it. I do have friends that would be able to make it out of aluminum though and I could have a plug made with a piece of square tube stock welded to that? Could you maybe recommend a size and thickness of tube stock? That is if you think it would be doable?

The sketches have helped me better to understand the proportions of what you're doing. It's a very different geometry from the kind of round-ish hull section of many GRP boats.

You're right, there is so much contact area on the sides of your plywood stack that you can afford a gap underneath it.

We all have to work with whatever tools, materials and skills we have to hand, so if a hardwood plug is not so easy, we have to look elsewhere.

I don't like the thought of a fabricated aluminum end plug, because I don't see how it can easily be tapered.

So I come back to your fig. 2 sketch, but with some taper in the hole, to suit softwood wedges. What I would do is:

1. Put in a piece of 3/4in plywood (well coated with epoxy) on edge between the two bulkheads, with its top horizontal. 
   
2. Bond a piece of plywood horizontally onto this, stretching from bulkhead to bulkhead, and bonded to the hull sides. Make two large holes, either side of the vertical plywood, for cables and drains. Flow-coat this deeply with epoxy, as the tube will rest on it.
3. Now build up the stack, maybe five layers of 3/4in plywood. The first layer to have an octagonal hole in it, 8.5in across flats. Subsequent layers to have an octagonal hole a little larger, until the top layer has an octagonal hole 8.75in across flats.
4. Soak the end grain with neat epoxy, then fill the steps in the hole flush with epoxy filler so that there is a reasonably smooth, tapered, eight-sided hole.
5. Make eight softwood wedges with a taper to match, 5/16in thick at the bottom, and long enough that there is something to get hold of to extract them when the mast is to be un-stepped.
6. Add the brackets and through bar to prevent rotation and lifting.

How does that sound?