Repairing Zipper Slider

A zipper that separates behind the zipper slider like the one shown on this tent is a very common zipper failure mode on backpacks and luggage too. It's an easy fix with a locking pliers: the goal is to carefully squeeze the top and bottom plates of the zipper slider just ever so slightly closer.

With the locking pliers in the locked position: use the screw adjustment at the back to close on the zipper slider. (Make sure you're clamping just the zipper slider and NOT the zipper pulls or fabric.)

Remove the locking pliers and tighten the screw adjustment ever so slightly: a 1/16th or 1/8th of a turn should be enough: you're trying to apply the slightest pressure to both sides of the zipper slider when you re-apply it.

Return the locking pliers to the proper position on the zipper slider and clamp the locking mechanism down: this time, the locking pliers should lock just a little as you clamp down. Clamp the zipper slider on BOTH sides with the same setting before changing anything.

It might take a few tries with successively tighter settings on the locking pliers but eventually the zipper will start zipping properly again.

This technique even works with pitched tents, which is typically when you figure out that the zipper needs fixing. It works on luggage, backpacks, any zipper that has a metal slider.

If you overdo it with the locking pliers the zipper might get hard to zip. You can open the gaps on both sides in the zipper slider a little with a thin flat blade screwdriver, but it's best to work slowly and avoid that scenario.