Sailmaking problem

[John of Phoenix]

I decided to make the sails for Harmony and bought a Sail-Rite kit. I’m very impressed. It has high quality everything; 4 oz Dacron fabric marked exactly how to stitch everything together, double stick basting tape, spools and spools of thread, leather for the corners, needle and thread for the leather, stainless grommets with grommet setting tools, the works. It even includes detailed step by step instructions with clever tips to help assemble everything. In spite of it all I’ve managed to make a mistake and I need some help to correct it.

Everything went well for several panels of the gaff main, two rows of zigzag stitches in each seam with an annoying, but acceptable, waiver in the lines of stitches. The little problem occurred in the longest seam in the main. The sail had gotten pretty difficult to handle and this part of the sail has a pronounced curve to make the belly of the sail. I basted the panels together pretty well, but as I sewed the seam, I put slight pucker in the seam. The pucker is less than 1/8” but it’s midway down the seam and about 3 feet from the bottom of the sail, which means it will be prominently visible. (CRAP, CRAP, CRAP!!!)

How to fix it?
1) It’s small enough that, in time, it will work it’s way out and become invisible.
2) Heat the area with a hair dryer and work the pucker into the adjacent area.
3) It’s gonna be there forever and drive you nuts. Everyone will point at your pucker and laugh. Rip out the seam and do it right.
4) Here’s something incredibly clever that you never would have thought of on your own.

It’s pretty much a “now or never” fix it or live with it situation. The next step is to put the binding on the edges. Once they’re on, it’s much more difficult (near impossible) to rip out and replace the seam.

Thanks.

[Todd Bradshaw]

Are we talking "pucker" as in "the tension went temporarily crazy and sort of wrinkled the seam so that it doesn't lie flat?"
If so, on 4 oz. cloth it will eventually probably smooth out, but few people would want to wait that long for something which bugs them to go away. It's probably better to rip out the stitching for the offending portion of that seam, check to be sure the basting is still smooth and re-sew the area. Overlap the old stitch lines for 2"-3" when you start and stop the new ones with no back-stitching, etc. It will leave a couple lines of old needle holes, but they will also usually get smaller with age. They'll bug you, but not as much as a puckered seam and structurally the sail will be fine.

It happens and you live with it. My sewing machine makes far more mistakes than I do :D - though I've been known to run out of bobbin thread right in the middle of the sail and sew three feet of empty holes before I notice what's going on. Luckily, my machine feeds accurately enough that I can go back over the area and hit most of the previous holes, so it doesn't show much.

[John of Phoenix]

Are we talking "pucker" as in "the tension went temporarily crazy and sort of wrinkled the seam so that it doesn't lie flat?"
Not so much the tension went crazy, more that I tried to pull things together to get the curve in one panel to match the straighter edge in the other. The result is the same though, one stitch with a little pucker that doesn't lie flat. ONE STINKING STITCH!

The bobbin runs dry on you too? I feel better, but to be able to hit the same holes the second time around? I know you're a pro, but THAT is impressive. :eek:

Thanks Todd, I appreciate your time.

[Todd Bradshaw]

One stitch? How big is the pucker? Have you tried pounding on it, stretching it or other means of redistributing the strain on it? If you do need to take out just a few stitches you can often re-sew them by hand using at least most of the same holes. You take a chunk of thread and put a household hand-sewing needle (not a big sailmaking needle) on both ends. Stick it through an existing needle hole about 1" before the area with the stiches missing and pull the chunk of thread halfway through. Then start sewing toward and across the hole from both sides until you've overlapped the good stitching again on the hole's far side. By sewing from each side and using the existing holes where possible you create what looks like a normal zig-zag and the areas at the ends where the new stitching laps onto the old hardly show at all.

In any case the seam tape will do most of the work, so you don't lose any strength. I once designed and built a Kevlar tri-radial mainsail for my Mini-12 that had 53 panels in a sail with about a 10' luff. The first time I hung it up at the ramp I heard a guy mumble to his buddy "that main probably cost more than the whole boat". Anyway, I got about a half-mile from the shore, looked up and noticed that I had forgotten to sew the big horizontal seam that connected the three radial sections, right across it's middle. Luckily, the basting tape was strong enough to keep it together because it would be pretty embarassing to be a sailmaker and have a brand new main split from luff to leech on it's first outing.

[John of Phoenix]

Well other than swear at it, I haven't done too much, but the hand sewing solution is the "Incredibly clever idea you'd never think of yourself." kind of thing I was hoping for.

Two needles! That's brilliant! Thanks.

And thanks for the story, too. :D

[Richard Smith]

You can't weigh the pucker against the holes - the pucker will be there forever - even after "a while." - and it IS a sign of poor craftmanship. (Needle holes are not.)

The holes will be erased - for the most part with age - filled with seam tape (which you should be using - not basting) - and the rest of the holes will eventually fade from your mind. But, never the pucker.

Rip it. Tape it. Resew it and hope to hit as many holes as possible. Then forget it. Its a sail, not a wedding dress!

If it still bothers you, step back further.

P.S. Don't heat dacon fabric. It breaks down the finish resin.

[Todd Bradshaw]

Seam tape and basting tape are two phrases for the same thing. Seams are basted together with double-sided tape which may be sold as seaming tape, basting tape, adhesive transfer tape or by specific brand names like Peko tape, Seamstick, 3-M Super Transfer Tape, Super-Tack, Venture Tape, etc.

Though there are differences between them like carrier type and thickness (Mylar, Dacron, Tissue paper or none at all) and the formula of the adhesive itself (acrylic or rubber-based) their function is basically the same. Whether they're called seaming tapes or basting tapes is strictly a matter of which term the person who wrote the catalog decided to use. The people at Sailrite often use the term basting tape in their catalog and instruction sheets, as do many of their customers.

[Andrius]

Originally posted by John Teetsel:
The little problem occurred in the longest seam in the main. The sail had gotten pretty difficult to handle and this part of the sail has a pronounced curve to make the belly of the sail.For those of us who haven't yet sewed a kit from Sail-Rite, is the lesson here to do the longest seam first?

A.

[Richard Smith]

Starting at the longest seam is not usually a concern - or prevention for the above. As Mr. Bradshaw indicates, seam tape is usually pretty tenacious - especially if you are using the "right" kind for the job. I like the rubber based type, which is very sticky. Although, it does yellow and degrade with time. If that is not a problem, and the integrity of the sail does not depend on seams being "glued," I would recommend it.

The big things to be sure of are: That you are not stretching one edge while sticking to the other, which can cause puckers, and to be carefull that your presser foot is not pushing a "wave" of fabric in front of it when you are sewing. The latter will not happen with good seam tape adheasion.

[Todd Bradshaw]

You can do the longest seams first, but I usually don't. I sew small sections together and then join the sections with the long seams. Back when I was building computer-cut radials some of them were bigger than the room I was working in and it was helpful to subdivide the sewing into two or three sections and then finally sew the sections together. No reason to be dragging 20' long panels through the machine when the seam you need to sew is only two feet long and way off on one side. On some of the big sails, I never got to see the whole thing at once until I finished it and took it outside, where I could finally spread it out.