Great gear is expensive and most people can’t afford to replace an otherwise perfectly functional backpack because of a zipper fiasco. With that in mind, I have put together this guide for how to fix a backpack zipper which covers all zipper related malfunctions.
Before I get started – A word to the wise: Many zipper fixes can be tricky or impossible without replacement parts such as an extra slider. Zipper repair kits are very small and worth adding to your first aid or sewing kit for a zipper emergency in the field.
First, I will cover some basic terms so that the instructions will make sense. Then, I will go through each different possible zipper problem followed by how to fix it.
Zipper basics: Parts and operation
Slider: This is the little moving box you slide along the zipper to make it open and close.
Teeth: If you look at the two sides of your zipper, you will notice it is made up of a series of individual parts called teeth. These teeth fit together by being “buttoned” one by one by the slider body. If you have a nylon coil zipper it won’t have teeth. Instead it has a continuous coil that works in a similar fashion.
Track: The length of the zipper made up of all the teeth.
Top/bottom stop: You will notice both sides of many zippers have a special fitting called the stop. This piece looks different than the teeth. Often a zipper on a backpack may not have a factory stop, rather, the zipper is sewn into the fabric on both ends which acts as a stop.
Pull tab: The part of the zipper you actually hold to move the slider body.
Tape: The fabric on either side of the zipper track.
Here is how a zipper works: The slider has two grooves inside that merge into one. When you pull a zipper closed, the slider buttons the teeth together. When you open a zipper, a wedge splits the teeth into two tracks.
There are several ways a zipper can stop working. This guide will cover the most common, and some strategies for fixing them.
Zipper pull broke off
This is the easiest fix. You can replace the zipper pull with anything that will fit through the hole that holds the zipper pull such as a scrap of fabric, dental floss or a piece of shoe lace.
If, however, the crown (that is the hole that holds the zipper pull on the slider) broke off, then your only fix is likely going to be to replace the slider. There are many zipper kits available for just this purpose. I will cover how to replace a slider a little further down.
Zipper is stuck
If your zipper is stuck on some fabric from your pack, the first step is to calm down and don’t try to force it.
If you have tweezers, start by using them to try to carefully pry out the offending fabric. It got in, it will come out. If you get frustrated, trust me, fabric is looser when you’re not stressed out. Come back when you can give it some patience.
Usually some lubricant applied to the teeth nearest the slider can also help. Graphite from a pencil can be one lubricant that is handy because it is not greasy. If you don’t have that, then lip balm or soap may work. Be patient and work slowly but surely and you will get unstuck.
Slider is only on one side of the track
Sometimes you can get lucky with this fix and just spread the teeth on the side that the zipper is not on by folding away from the center, giving you just enough room to slip the back of the slider between two teeth and then feed the slipped track towards the front of the slider until it is back inside.
If you have a zipper made of a soft enough metal to bend, you can also try slightly opening the gap on the back of the slider with some small pliers or your pocket knife. If you are dealing with a plastic or brittle metal zipper, trying to open that slider is likely going to break it.
If you are able to get the zipper back on track then even out the zipper tracks on either side and pull the zipper to the fully open position. If you loosened the slider, now is the time to gently tighten it back down before zipping closed again.
Zipper is not closing
If your zipper slides up and down the track, but does not close the zipper there are a few possible fixes.
If you have a metal slider, you can try crimping down on it a little bit with a set of pliers. Be very careful with this because there is a chance that the zipper may just shatter as sliders are often made with metal that is brittle. It doesn’t take much though, and this is definitely a first try solution because it is easier than the alternative.
The alternative is that you are in the unfortunate position of having to replace the slider altogether. This can be tricky, and if you are in the field, likely impossible unless you packed a zipper repair kit.
If you are at home and can order a replacement slider set, then you will be able to do this repair. If you have a high-end backpack, chances are the manufacturer sells specific zipper repair kits with the replacement sliders and extra stoppers you will need for this repair.
Start by pulling the zipper all the way to the back of the track as far as you can then cut between the teeth on both sides, just ahead of the slider. This will allow you to get the old slider out, and put a new slider on. Then you will need to put a stop from your kit (or sew one) behind the cut you made in the track.
For a helpful tutorial video on replacing a slider, check this out.
Missing a tooth
This is probably one of the most tedious zipper repairs to do. If your problem is a missing tooth on your zipper there are a few different solutions that might work.
First, ask yourself if the missing tooth is near the bottom of the track. That is, if you can still use the pocket if it stops at the spot where the tooth is missing, the easiest and fastest fix is to install a stop before the missing teeth.
Such a stop is easy: Use your sewing kit to sew multiple times across the zipper track above the missing tooth so the slider will stop before it hits the missing tooth. Done.
If the missing tooth is in the middle of a critical pocket, you will have to try to replace the tooth with a tooth from a less critical spot on your backpack.
If you have a metal zipper you are in luck. Usually metal teeth are just crimped on, so they can be loosened and moved fairly easily with some patience. Use your pocket knife, or a seam ripper from your sewing kit, to pry off a less important tooth, then reattach it to the critical spot.
With plastic zippers you may need a razor or a very sharp pocket knife to cut out individual teeth from a spot that is less critical (the end of a track, or a less important zipper on the bag). You will need to then dig out the fabric that is lodged from where the tooth was removed. Then, it is ready to reattach with some super glue to the spot where it is needed.
Getting the tooth on to the tape can be challenging. Use the knife and/or seem ripper to press the fabric into the small slot at the base of the tooth. Make sure to get it aligned properly, and give it a test run before you carefully use super glue to secure the tooth.
If you remove a tooth from the end of a track, then you need to fashion a stop so the slider will stop before it hits the spot without teeth and derails. You can do this by folding a small scrap of thick fabric and sewing it to the tape, or simply sewing across the entire track.