Stitch changes quality mid run

[Albob]

So a few weeks ago I bought a singer 111W155, contacted Bob at Toledo Sewing for a servo motor. I've been getting better and learning how to use this (My first ever sewing machine)

However I cant figure out how to stop this issue. When sewing up a wallet (THANKS JLS) I get a loose loop when I transition from double layer to single layer. I have the tension correct for the project 4/5 oz. veg tan running 138 thread top and bottom through #22 needle. I'm wondering if it is the lack of contact cement in the area of one layer? (Water based Weldwood)

I hope I explained it right, anyway here's a picture of the area I'm having trouble.

Thanks in advance!!

Fredo, San Diego CA

[l2bravo]

I wouldn't say you have your tension correct. See all the knots?   Too much top tension. As for your loose loop, you can adjust your pressed foot, stitch length, or how you feed it.  Good luck.   

[l2bravo]

One more thing, 138 should get a 23 needle. Might be a part of the problem.  

[gottaknow]

When you sew on one layer, unless the leather is thicker, there's no place for your knot to sit. Usually it would be between the two or more plys. It appears your top tension is too tight. Let the stitch pull down a bit towards the bottom by loosening your top tension or tightening your bobbin tension, or both. I can see even on your two ply that the knot is being pulled up too far. Also, a size 22 needle is fine with 138 thread. We use that combo all the time with no issues. 

Regards, Eric 

[Albob]

Thank you everyone for your thoughts. I'll fiddle around with it some more.

[l2bravo]

Gottaknow, knowing that you generally have your stuff together, tell me about the needle reccomendation.   I use and like 138 a lot.   I've always used the 23's.    I sew a lot of softer oil tanned, double and maybe triple 5 oz.  Would 22's work for me, or better to leave it where I'm at?  Thank for the help. 

[gottaknow]

I've always found it interesting that people get locked into needle sizes and threads based on charts. The charts are generally meant to be guidelines, and a good starting point if you're unfamiliar with common combinations.  I usually tell folks that the correct needle size is the one that looks and works the best. As a mechanic we are tasked with using the thread size that is assigned to a particular product. A common thread for us is T60 in a Poly/Cotton thread. I use it in needles from size 16-21 depending on the fabric and thickness. When I'm bartacking 6 layers of heavy 26 oz. Pendleton wool I use a size 21 with the T60 thread, when per-serging a single ply of the same wool, I'll use a size 16 needle. Too many people get hung up on the charts. I encourage people that have been sewing a while to experiment with different combinations and don't feel like you're doing some wrong if you vary from the sacred charts. Use what looks and works the best. This applies to leather as well.

Regards, Eric

[RockyAussie]

Several problems... The needle size looks a little to large which makes the drag of the knot too easy to pull to the top but from my experience the design is more the red flag. Always on thinner type products design where you stitch to be of a similar thickness. Either skive around the outer edges of the 2 credit card pockets or whatever to about 1/2 thickness if you have a skiving machine or design a bridge section into the middle of the same thickness. Most of my wallet designs have a short filler at the bottom of wallet (skived a bit and tucked under) and a full length strip about 20mm or 3/4" inch wide at the top. I hope you find this of help and note that softer leather liners will help a bit  also.

Regards Brian