Sewing back a loose zip coil

If the zip coil has started to come away from the tape, the zip splits open quickly. Usually this means the whole zip has to be replaced — but if it is only a small section that has come loose, you can save it by sewing a straight stitch over the coil.

Worth a try before you replace it. If it works, the repair can hold for several years.

When this works

• Only a short stretch has come loose (1-3 cm)
• The coil itself is intact — only the fastening is weakened
• The thread in the tape around the coil is still usable

For longer loose stretches or a damaged coil: replace the whole zip — see Replacing the front zip on jackets.

What you need

• A sewing machine with a straight stitch
• Thin but strong sewing thread — polyester thread is good
• Patience

How to do it

1. Start ~1 cm before the point where the coil has come loose, from the intact part of the coil
2. Set the stitch length to 1 or 2 (short stitches) and a straight stitch
3. Turn the sewing machine by hand — let the needle go between each coil section, not through them
4. Reposition the garment if the needle hits a hard part of the coil
5. Adjust the stitch length so it matches the spacing between the coils
6. Stitch back and forth twice at the start to lock the seam — only twice, to avoid a lump the slider won’t glide over
7. Carry on the whole way by hand until ~1 cm past where the coil had come loose
8. Lock the seam by stitching back and forth at the end

Why manual operation

In auto mode the sewing machine runs too fast and often hits the coil sections directly — crushing or bending them. Turning by hand lets you control each individual stitch and avoid the coil.

Test before use

Before you take the garment on a long trip:

• Test the zip 5-10 times
• Pull it hard — if it is going to break, it will break now
• Check that the slider does not catch on the stitching

Prevention

• Don’t pull the zip hard when it catches
• Lubricate the coil with wax or silicone spray now and then
• Check regularly for threads coming loose from the tape — catch it early before the coil starts to come away

Back to Repair → · Replacing a zip slider → · Replacing the front zip on jackets →

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Text: Lars Peters and Snuitide (2022), revised 2026.