Singer 15-91 ugly bottom stitching
 

First, let me qualify: I have no experience sewing, save for sewing a patch on a uniform or an emergency repair... That being said, I purchased a Singer 15-91 because I read that it is a good machine for sewing marine canvas. Which I have, in need of repair. Sunbrella is the brand of canvas to be specific. At any rate, after about 4 hours or reading, experimenting, and cursing, I was able to successfully make it stitch without a) breaking needles, or b) jamming up into a tangled mess. However, I am still getting ugly bunches of overlapping thread on the bottom on the material. Topside looks great. Details: I am using a #14 singer needle with Gore Tenera V92 thread. I guessed at the bobbin tension, and the top tension is pretty much in the middle. (Tenera is very slippery, as it is basically PTFE, or teflon.) I'll be sewing through about 2-3 layers of sunbrella canvas. Any ideas?
The full size image is here:http://www.pbase.com/mchad/image/144031062/original - it's too big to display here.
http://www.pbase.com/mchad/image/144031062.jpg

Sometimes it could be that it's threaded incorrectly or the needle is in the wrong way. I hope it's a simple solution that solves the problem.

When this happened on my Featherweight the bobbin case/shuttle was in wrong. I have a 15-91 and love it. I haven't taken the bobbin case out before, it is quite similar to the featherweight so hopefully that will help you Do you have the instruction book for your machine? Hopefully you have it, look at pages 30 - 31. It tells you how to clean the Stitch forming mechanism.

Here is a website of the manuals - just find yours

http://www.ismacs.net/singer_sewing_...e-manuals.html

I too have a 15~91. Make sure there is no fuzz or threads in the bobbin case. I just blow it clean or use a make up brush when i change bobbin threads. Also rethread it again from the start. It may look right buta little off. It is sewing fine for a bit so looks like may just be dirt or thread off. Make sure the needle is threaded right. Mine is right to left and the bobbin thread is in correctly. I love mine. Its about all i use anymore!!!

A 14 is a pretty lightweight needle for heavy sewing like you're doing...try a jeans needle, or a 16 or 18...

I agree with Charlee...the eye on a 14 is probably too small for the thread to pass thru easily & I'm thinking it's not really heavy enough for the fabric either.

I'm impressed with the number of good suggestions, so quickly. I do have the manual, so *I think* I have it threaded correctly, but I will confirm. I'll also check the mechanism and clean the case as suggested, and report back. I do have a 16 needle which I will try as well. Thanks all.

Do not pay attention to the number on the tension. It would be easier to see than to explain how to adjust the tension. Here is a link I started a long time ago - I didn't check to see if they are all still there: http://www.quiltingboard.com/vintage...s-t170748.html anyway it is a bunch of links. It could be that you have the threading wrong around the tension. The thread comes across the top of the machine, goes through the tension, through the tension spring, over the bar, then up through the take up lever. If you do the spring after the bar and then go from the spring straight up to the take up lever it might do weird stuff.

The Sunbrella should be light enough to be sewn by a Singer 15 if the project isn't too huge. If it is a large piece you may have to 'help' the fabric through the machine. When I made a 30 X 50 foot awning, I used some ramps and I folded the material a lot. I was using a Consew walking foot sewing machine. I wonder if you got the tail end of the thread caught in there? You can go up to about a size 18 needle - any bigger and your machine can't handle it very well. The needle won't fit the hole/bobbin/shuttle quite right and an over sized needle on that machine could damage the bobbin case or the shuttle or the throat plate and could make burrs. Trying to pull too much heavy fabric through could bend the needle shaft or the needle. The other thing I can think of that could make stitches like that could be a burr on the hook or somewhere. You have to feel around and then polish out the burr.

Can you shoot a picture of your machine threaded up - shoot the nose end with the tension?

That is exactly how I had it threaded. I though that is how the instructions said to... I must have been reading it wrong! I don't have time to try it now, as I have to go to work, but I will later tonight and check back.

Here is a photo, and here is the full size, where you can clearly see the route around the tensioner... http://www.pbase.com/mchad/image/144038814/original.jpg

The only thing that is not clear is that the thread goes through the needle from right to left after the last hook at the top of the needle "holder?"

Thanks again

http://www.pbase.com/mchad/image/144038814.jpg