Chinese shoe patcher and thick leather

[stevemaynard]

Hi All

I just bought an el-cheapo chinese shoe patcher and have it sewing thin leather (<2mm) together and thin to thick leather (3.5mm , roughly 1/8") , but when I try to sew thick to thick leather the thread snaps or is sheared off. I have tried using the waxed linen thread from a speedy stitcher as well as Getterman linen thread as well as varying the tension I have a 100/16 needle on the machine. I would prefer to use natural fibre thread if possible as I am wanting make stuff to sell to medieval re-enactors. Any thoughts or suggestions appreciated.

[Colt W Knight]

Have you tried a larger needle size?

[Matt S]

What is the total thickness of leather you are trying to stitch? Patchers are not designed or capable of anything much above 6mm. Can you provide a picture of your work? A size 100 needle should be used with a synthetic TKT40/V69 thread, which is a size often used on commercial wallets and purses -- much smaller than the threads usually supplied with those lock-stitch awls and smaller than any linen thread I think I've seen. TKT40 is towards the largest you can reasonably expect to use in your patcher.

Linen thread is a little difficult to use through a machine, as it has zero stretch. I believe that the machine has to be designed with it in mind, and linen threads have not been common in industry in decades. Prewaxed linen is especially sticky, and machines supplied for its use had heating apparatuses to soften the wax before it got sewn. I realise that you want to use natural materials for a more period-correct product but If that's your aim you should be hand stitching in my humble opinion, using tools and techniques appropriate to the time and region.

[stevemaynard]

4 hours ago, Colt W Knight said:

Have you tried a larger needle size?

That is my next experiment, when I get the chance

[stevemaynard]

3 hours ago, Matt S said:

What is the total thickness of leather you are trying to stitch? Patchers are not designed or capable of anything much above 6mm. Can you provide a picture of your work? A size 100 needle should be used with a synthetic TKT40/V69 thread, which is a size often used on commercial wallets and purses -- much smaller than the threads usually supplied with those lock-stitch awls and smaller than any linen thread I think I've seen. TKT40 is towards the largest you can reasonably expect to use in your patcher.

Linen thread is a little difficult to use through a machine, as it has zero stretch. I believe that the machine has to be designed with it in mind, and linen threads have not been common in industry in decades. Prewaxed linen is especially sticky, and machines supplied for its use had heating apparatuses to soften the wax before it got sewn. I realise that you want to use natural materials for a more period-correct product but If that's your aim you should be hand stitching in my humble opinion, using tools and techniques appropriate to the time and region.

I haven't actually started on a piece, just using some scraps to experiment with.
I was given the impression by posts elsewhere on the net that it could handle up to 9mm/ 3/8" but if 6mm is the limit I will adapt .
I take you point about using period techniques while ideal it increases the price as the volume is low, so I'm trying to find a happy medium to be able to reduce the price.

[dikman]

I tend to agree with Matt regarding thread size, I doubt if it's designed for anything more than #69/M40. The bobbin is also pretty small to get much thread in if it's bigger. Needles are questionable in this machine, mine came fitted with a standard domestic needle.

[Darren Brosowski]

There could be a number of problems.

Most likely the foot is lifting as the needle comes up so the loop is not forming properly. The foot pressure is controlled by the nut under the top arm that tensions the two springs that run through the upper arm.

If not then you may need to drop the needle bar a poofteenth of an inch