How to sew lightweight fabric without puckering?

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

Hello everybody,

My first post here. I was told I could find a number of knowledgeable people regarding sail sewing here. I'd like to ask for some help and advice, if I may.
As the summer approaches, there is a need for a new sail for my little boat (the old one is shredded), and I find myself in a frustrating setback.
I am trying to make a sail from a lightweight 4.7 oz polyester fabric, since Dacron is not available in my country. I have the whole sail cut and panels joined with sticky tape, but my sewing machine won't cooperate. It's an old, Russian Podolsk 142 model.

The problem I'm having is seam puckering. My seams are 1/2 wide, and I want to do wide zig-zag stitches along each edge of the seam. I am using 12/80 needle and no.45 universal thread, both high quality. Here are some photos of what's happening, it's a medium width stitch (I'd prefer wider):

1 2 3 4 5 6

What I have tried already:

1. Lowering bobbin and top thread tensions - doesn't seem to be making any difference, even when the tension is so low that the thread "floats" above fabric;
2. Smaller needle - even with a 10/70, puckers are still there;
3. Lighter thread - makes no difference, and anyway, I want seams to be strong, so it doesn't make any sense to use weaker thread;
4. Lowering foot pressure - no difference, either;
5. Stretching the fabric as it is being fed through the foot - only makes matters worse;
6. Narrower zig-zag - helps a little, but the pucker is still there even with a straight stitch, and in a sail, straight stitch is not acceptable...
7. Zig-zag with an intermediate stitches - worst pucker of all.

If I break the stitches, and remove every bit of the thread, the pucker is sort-of gone, but not completely.

I have tried sewing other, thicker materials (like rags, socks, etc.), and the machine does not pucker them. Only my polyester fabric.

I am running out of ideas. I have been fighting this machine for a week now, 3-6 hours a day, with no positive results. What you see in these photos is the least pucker I could produce. I tried every combination of thread tensions, needles, threads, foot pressures, etc. I could think of.

 Thank you in advance. I really hope I won't have to buy a new sewing machine...

Edited by laukejas - 25 May 2016 at 11:08am

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
laukejas Members Profile Send Private Message Find Members Posts Add to Buddy List Forum Member Joined: 25 May 2016 Status: Offline Points: 2	Post Options Post Reply Quote laukejas Report Post Thanks(0) Quote Reply Topic: How to sew lightweight fabric without puckering? Posted: 25 May 2016 at 11:07am
	Hello everybody, My first post here. I was told I could find a number of knowledgeable people regarding sail sewing here. I'd like to ask for some help and advice, if I may. As the summer approaches, there is a need for a new sail for my little boat (the old one is shredded), and I find myself in a frustrating setback. I am trying to make a sail from a lightweight 4.7 oz polyester fabric, since Dacron is not available in my country. I have the whole sail cut and panels joined with sticky tape, but my sewing machine won't cooperate. It's an old, Russian Podolsk 142 model. The problem I'm having is seam puckering. My seams are 1/2 wide, and I want to do wide zig-zag stitches along each edge of the seam. I am using 12/80 needle and no.45 universal thread, both high quality. Here are some photos of what's happening, it's a medium width stitch (I'd prefer wider): 1 2 3 4 5 6 What I have tried already: 1. Lowering bobbin and top thread tensions - doesn't seem to be making any difference, even when the tension is so low that the thread "floats" above fabric; 2. Smaller needle - even with a 10/70, puckers are still there; 3. Lighter thread - makes no difference, and anyway, I want seams to be strong, so it doesn't make any sense to use weaker thread; 4. Lowering foot pressure - no difference, either; 5. Stretching the fabric as it is being fed through the foot - only makes matters worse; 6. Narrower zig-zag - helps a little, but the pucker is still there even with a straight stitch, and in a sail, straight stitch is not acceptable... 7. Zig-zag with an intermediate stitches - worst pucker of all. If I break the stitches, and remove every bit of the thread, the pucker is sort-of gone, but not completely. I have tried sewing other, thicker materials (like rags, socks, etc.), and the machine does not pucker them. Only my polyester fabric. I am running out of ideas. I have been fighting this machine for a week now, 3-6 hours a day, with no positive results. What you see in these photos is the least pucker I could produce. I tried every combination of thread tensions, needles, threads, foot pressures, etc. I could think of. Thank you in advance. I really hope I won't have to buy a new sewing machine... Edited by laukejas - 25 May 2016 at 11:08am

wingless Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Member Joined: 30 June 2013 Location: Florida Status: Offline Points: 135	Post Options Post Reply Quote wingless Report Post Thanks(0) Quote Reply Posted: 25 May 2016 at 1:02pm
	Welcome to the forum.
	2000 SeaRay 380 Sundancer Mercruiser 454 MAG MPI Horizon 380hp Westerbeke 7.0KW BCGB many cool mods Juki DNU-1541S Consew CSM550