I'm modifying/repairing a backpack, and have once again encountered a problem that's fairly common with outdoor gear. In this case it's exacerbated by sewing a very thick stack of fabric where seams come together.

The waterproof coating (probably polyurethane on nylon this time) leads to a lot of friction for the needle. Friction is worse with thick needles but these tough fabrics break thin needles easily. It's not uncommon for my machine to stall with a thick needle, and even those can break. When hand sewing the difficulty isn't in breaking through the coating, but increases as thicker parts of the needle pass through the hole. Even the thread is subject to quite a bit of friction (more of an issue sewing by hand than with a basic machine stitch).

Is there a good way to lubricate the needle as it passes through the coating? I'm not sure oil is a good idea on such fabrics, but (soapy) water can make the fibres swell and I'd be worried about it dripping inside the machine as the foot compresses the fabric.

1 Answer 1


I would recommend using spray silicon as a lubricant. Just check to be sure it is compatible with the materials, although the amount that might transfer would be negligible so probably no worries. We used it in the sail loft I worked in for that very same reason.

  • 1
    Silicone should be very compatible with some coated fabrics at least, as many of the coatings are themselves silicone, though obviously the solvent/carrrier liquid is also relevant. I'll have a look at getting some (I think the hardest part of this job is done now and a comfy old spare backpack will soon double as a bike pannier)
    – Chris H
    Nov 8, 2022 at 17:23
  • It does make things super slippery, and its a dry lubricant so I doubt it would act as a solvent unless you accidentally spray the material when lubing the needle. As I recall we were pretty liberal with it, and would spray the table as well to keep things moving.
    – rebusB
    Nov 8, 2022 at 17:27
  • I think the carrier for the dry sort is usually butane. I'd risk overspray on the fabric.
    – Chris H
    Nov 8, 2022 at 17:30
  • Spray before you sew. It should last a while. When it gets sticky clear the machine, lube, and then go back to the material. It is good practice anyway.
    – rebusB
    Nov 8, 2022 at 17:33

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