Thread: Sailmaking 101 for Goat Island Skiff, Beth

Not hard. If you know how to use the machine, it's just matter of working with an awkward over sized workpiece. Home machines will be challenged by the multiple layers where corner reinforcements and edge tapes all converge. I have places that are ten layers thick ( of. 4 oz cloth). My machine did it but it was clearly at the limit. I also have a triple zig stitch option. See if you have that or single or no zigs at all. Advise Sailrite of your findings.


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Christmas present, I'll be sewing soon!

Wow! Ambitious much? Them's a lot of seams... I hope I didn't downplay things too much. I meant to say, "sewing five seams that go from one side of the sail to other is not hard." Your design more than triples that count and throws in the challenge of the two horizontal seams that join vastly different shapes together. I trust the software will describe the appropriate curves for those junctures; the question is how well they all line up in 3D.

That said, tell us more about the concept. What were the assumptions and decisions that went into it? I would love to have seen panel 15 span the full length of the head uninterrupted. Then again, my own sail (and many others) has two seams intersecting the head, so I can't say I have good cause to feel that way.

Like any interesting innovation, you've raised as many questions as you've answered. Please tell MORE, MORE, MORE!

Boring story actually. Jeff said that a cross cut would work really well, but I want to try something a bit different just for the fun of it, knowing full well that it may not have any performance benefit over a cross-cut. This is what he came up with, it's a slightly modified bi-radial. I like the way it looks - I mean it looks fast. The funny thing is that when sailing last Saturday, I was sailing next to a J27 coming back into the harbor, and his laminate main had a very similar panel layout. We were talking away, sailing side by side, until we noticed we were about to run over a pram coming the other way.

Yes, I think it is ambitious, but what the heck, if I'm going to make a new sail, might as well jump in the deep end, and further the Goat community by trying something new!

There is an advantage to the radial cut design for rigs with bendy masts that is very well documented. The radial cut allows the optimum orientation of the warp/weft foreach panel and as a result of the material wastage involved, the sails are more expensive. The advantage is a sail that that is more powerful when fully powered up, but can also be depowered much more than a cross cut sail, so it is more versatile across a range of conditions. This is for bendy flexible rigs, like Finns, Lasers and other stayed rigs where mast bend is employed. An example is the Laser Radial which although being more than 1sqm less in area than a standard rig, is just as quick upwind in a strong blow. (The standard rig is quicker downwind though, purely on the extra horsepower from the larger sail)

However, the lug rig depowers differently by the yard falling away in much the same way as any square top sail, so I have my doubts that the radial cut will offer any performance advantage over the cross cut. Having said that, you can use a lighter cloth for the radial, because the panels all help to reduce stretching, so that is quite a good thing. The radial cut certainly looks cool, so is as good a reason as any to make it!

I'm having him add a bit more yard edge rounding for my whippy yard, and more foot rounding (loose footed) for more power. Probably should have snuck a window into the design, but then I would have no excuse for the collisions.

Originally Posted by warm beer

...but then I would have no excuse for the collisions.

Is that what you told the pram? "Sorry! No windows!"

I look forward to more progress reports on this interesting project!

missed the pram. most recent ramming was broadside on a kayak that came from underneath me, before that a fuel dock (that must have been under power).

Originally Posted by warm beer

Awesome sail today!

The link Dave gave to the discussion on lug sails shows a sketch of a tri-radial lug. I'm wondering if Sailrite could map that out!

Howdy WarmBeer

I am sure they could. It means more fussing around aligning strange shaped bits - why not ask! Report back too please.

MIK

... sewing, sewing, sewing ....

what I've noticed so far
(1) my machine works best when I make sure the thread is channeled the way it's supposed to be. Duh.
(2) to bast seams that are 3D, I put them over a slightly domed plastic "bucket seat" - a seat lid for 5 gallon buckets, works really well. In honor of Mik, and while going stir crazy sewing, I named it the "Thunder Dome"
(3) sail cloth slides easily over sail cloth, so my sewing rig is two folding plastic tables strung end to end with the machine in the middle, on top of this I have gymnastic mats that bring the table surface to the level of the machine feeder. Over that I have the extra sailcloth. Hmm. Maybe I should take a picture, that might be easier to explain.
(4) to keep the extra cloth rolled up to fit under the machine arm, I found that if I roll it up with a rattan beach mat roll at the same time, it does not try to unroll. Like a sushi roll with a layer of rice rolled up with the seaweed. Maybe a picture again.
(5) the new cloth is 4 oz supercruise, my old cloth was 3.8 oz dontknowwhatcruise ... but the new cloth is thinner and more flexible. Go figure.

Here are a bunch of pictures
At this point, I have 12 of fifteen internal seams sewn with two rows of tricot stitches, and 5 of eight patches sewn in place. The sail is in four sections, to be joined later, after adding the rest of the patches and the batten pockets to the sections Pretty quick so far, started sewing at 10, quit at 5. The pictures are all in this album, where you can see them bigger: https://www.woodworkforums.com/member...-construction/

(0) the layout

(1) thunderdome hard curved basting surface

(2) thunderdome sort of in action, I flattened out the small crinkle in the basted seam, after removing the basting backing.

(3) good stitches

(4) not as good stitches (pucker, the bobbin tension wasn't right)

(5) tack patch

(6) throat patch

(7) radial clew partially assembled

(8) the rig

(9) the rig at work

(10) level surface - I did not want to sew on the floor, my back would not like that, so I made a big worksurface with the machine in the middle
two tables supporting two gymnastics mats. I put chalk on the mats so the sailcloth slides easier.

(11) the mats also bring the cloth up to the height of the machine, so everything feeds easy without folding.

Hey Dave (or other sail making veterans),
I'll be setting the grommets soon, and am curious what the best way is for placing them. I have #4 and #0 brass grommets (partial to brass), and die sets for both. The Sailrite instructions have been extremely clear and easy to follow so far. They say to make a male grommet sized x cut for the grommet. I have read tricks on other threads where they burned the grommet holes with something hot.

I'm also anticipating that rolling my sail tight enough to join my sections is going to be a challenge. Any tips?
Andy

Mey Mik, I put the pictures on the facebook site too.

I don't have any special advice for the grommets except to recommend the "spur" grommets over plain. Spur grommets have teeth that dig into the cloth increasing the bond between the two. If all you have is plain and have no desire or patience to change, then melting the hole might add some additional strength. But the hole can still be distorted under tension and the fused edge won't prevent that, it will only prevent unravelling of the weave.

Originally Posted by davlafont

I don't have any special advice for the grommets except to recommend the "spur" grommets over plain. Spur grommets have teeth that dig into the cloth increasing the bond between the two. If all you have is plain and have no desire or patience to change, then melting the hole might add some additional strength. But the hole can still be distorted under tension and the fused edge won't prevent that, it will only prevent unravelling of the weave.

They are spur grommets in brass. Haven't placed them yet, but I picked up a set of hole punches and fancy no-recoil hammer for cheap at Harbor Freight. The Sailrite video for grommet setting shows them using the hole punch.

Next question - how did you finish the corners? I've ssen where they recommend using a hot knife for rounding off the peak, but I don't have a hot knife.