Questions About Tension And Thread Choice

[becky]

After years of quilting, and then moving on to sewing chap leather, I decided I wanted to start working more with tooling leather, making holsters, portfolios, and bags. I am not ready to invest in an industrial machine. I did, however, find a Singer 15K88 to use, and after cleaning it up, it sews like a dream. Using a 110/18 leather needle, it sews right through up to 3 layers of tooling leather, no problem. Honestly, I don't know how heavy the leather is, but basically, whatever I can fit under the needle, the machine will sew through. The problem I'm having is with the thread. I started out using Coats & Clark upholstery thread (nylon) and the machine liked that thread just fine. But it didn't really have that nice looking stitch line on the leather because the thread was too thin. So I tried two other thread weights including Dual Duty Heavy and Dual Duty Button & Carpet threads. However, because the thread is heavier, I can't seem to get the tension adjusted correctly. The machine is pulling the top thread down to the bottom, and even after loosening the bobbin tension as much as possible and tightening the tension on top as far as it would go, I can't get the tension right. Is there any way to modify the machine to take the heavier thread? Or some other trick? Or a different thread I should be using? Any advice?

[Wizcrafts]

Becky;

I happen to have a Singer 15-91, which is pretty much the same machine you have. Mine has the Pod motor built into the case, whic I rebuilt.

Before I bought my walking foot machine I used that 1950's Singer to sew everything from leather to vinyl, up to 5/16" thickness.

I found that the machine does not want to sew with anything thicker than V92 /T90 bonded nylon on top and V69 /T70 in the bobbin, because of the same tension issues you found. But, I unwound the top tension disk assembly and rethreaded it so the spring and front numbered plate went all the way around and it did indeed squueze the thop thread sufficiently to get the knot in the middle of a 1/4" thick belt. Another trick is to use a #20 leather point needle, which I found on eBay. That needle makes a bigger hole and makes it easier for the thread to pull up the knot.

I hope this helps you out. Don't expect anything more from these little old machines, as they were designed for light duty sewing.

If you ask around I'm sure you can find a dealer on this forum who sells used leather sewing machines. Bob Kovar, of Toledo Industrial Sewing Machines is one who does. He has lots of old and rebuilt machines in his warehouse. A Singer 111W155 is a good starter walking foot machine that can be had dirt cheap. Have a servo motor added, in place of the clutch motor, and you can sew up to #207 bonded nylon on top, in these machines, with #138 in the bobbin. Bob also sells all weights of nylon thread and all needles and bobbins and has lots of spare parts. I get stuff from hime all the time.