If you have a stuck waterproof zipper or if you feel that your waterproof zipper is hard to open (harder than it should be) then this is a guide that can help you out. There are a couple of different reasons why a waterproof zipper won’t open or why an airtight zipper is hard to open. But first, a few facts about how these zippers work. This will help you understand why more resistance is also normal.
How Do Waterproof (Airtight) Zippers Work?
Waterproof and airtight zippers are very similar, but not exactly the same. Because of their size and shape, air molecules can pass through smaller gaps than water molecules. This means a zipper needs to be more precise and tightly sealed to be truly airtight than it does to be just waterproof. The difference is small, though, so in many cases the two terms are used interchangeably.
Both zipper types work in the same way. They are designed to prevent water and air from passing through. This is achieved by interlocking zipper teeth covered with a continuous layer of flexible material, such as polyurethane or rubber and/or by using zipper teeth to force this material together from both sides so it makes a seal. In both cases, when you close the zipper, the teeth press this material together, forming a solid barrier that water and even air cannot penetrate.
To get a good seal waterproof zippers require the teeth to press together much more tightly than in regular zippers so even microscopic gaps can be compressed and closed. The pressure needs to be even bigger when it comes to airtight zippers. The downside is that this makes waterproof and airtight zippers harder to open than standard zippers. It is also normal that an airtight zipper will be harder to open than a waterproof zipper. But this also greatly depends on the design and brand of the zipper so main thing to remember here is that it is normal for these zippers to be somewhat harder to operate.
What exactly does it mean harder? A good explanation is that you usually need both hands to open waterproof zippers. One hand to hold the material at the top of the zipper and the other to pull on the slider. With regular zippers you can open them with just one hand.
If you find that the waterproof zipper on your dry bag or waterproof backpack is stuck, here are the most common reasons and solutions, based on our experience with DryTide backpacks.
How To Fix a Stuck Waterproof Zipper and Other Problems
1. Zipper is hard to open or close
If you read the section on how waterproof zippers work you know it’s normal for them to require more force than regular zippers. If you still think that you have an unusually stiff zipper on waterproof gear and you want it to move more smoothly, a silicone-based lubricant can help (check DryTide Zipper Lubricant).
HOW TO LUBRICATE A WATERPROOF ZIPPER?
Apply only a tiny amount of zipper lubricant to the top zipper teeth, then gently open and close the zipper a few times. The zipper slider will spread the lubricant along the teeth, making it run more smoothly and reducing the force needed to pull. Make sure you do not use an oil-based lubricant, as these attract dirt, the opposite of what you want for a zipper.
Is zipper lubrication necessary? The zipper will work fine without it. Lubrication is simply an extra step to make opening and closing easier, while also protecting the zipper and extending its lifespan.
2. Completely new backpack, zipper is stuck
On a brand-new backpack with a brand new zipper that has never been opened it is common that the zipper head may stick slightly or feel “baked” to the zipper material. People usually hesitate to pull too hard, because they are afraid of tearing something. If this describes your problem then this is how you should try to open it.
Hold the top of the zipper and the backpack material with one hand and pull the slider with the other. Always pull in a straight line, never at an angle. You can pull as hard as you can; if anything tears, we will provide a replacement (this goes for DryTide backpacks, please notify us beforehand).
This solves the problem in 99.9% of cases. Once the zipper has been opened the first time, it becomes much easier to operate.
3. Completely new backpack, faulty zipper
If the zipper still does not move despite pulling with full force, it may be defective. This is extremely rare; so far, we’ve encountered only one such case. If you cannot open the zipper after following the instructions above, please send us a video showing how hard you are pulling, and we will guide you from there (again, this goes for DryTide backpacks).
4. Used backpack, stuck zipper due to salt deposits
If you have been using your bag for a while and you suddenly discover your airtight waterproof zipper is stuck, there can be several reasons. The most common and the only one we’ve observed (and more than once) is salt buildup from saltwater exposure.
Prevention: Rinse your backpack and zipper with fresh water after every saltwater use.
If you are reading this then the salt crystals have probably already formed. In this case follow these steps:
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Gently brush away visible salt using a soft brush, such as a toothbrush. Do not force open the zipper.
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Soak the zipper in fresh water to try to dissolve the salt. (This never worked for us, but it does not hurt to try.)
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If the zipper remains stuck, use a mild acid rinse: mix 1 part white vinegar with 3 parts water, dip a cotton swab or toothbrush in the solution, and gently work on the zipper teeth and slider to dissolve the salt.
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After you open the zipper, rinse it thoroughly with fresh water to remove any remaining vinegar.
This method dissolves stubborn salt crystals without damaging most zipper materials. Avoid prolonged contact with the zipper or backpack fabric.
5. Used backpack, stuck zipper due to debris
Less commonly, zippers can become stuck from dirt or debris caught between the teeth. Prevention is key: keep the zipper clean before closing it.
If debris is already lodged:
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Use a brush to remove what you can from the outside.
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Tweezers can help pull out dirt stuck between the teeth.
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Apply a small amount of silicone lubricant to help the slider move. Gently work the zipper up and down until it passes over the problem area.
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Once the zipper is free, clean out all remaining debris. Debris can damage the waterproof zipper by making indents on the material that makes the seal. So close the zipper and test the seal before you rely on it again.
6. Used backpack, stuck is zipper
This is also rare, but it can happen. If you did not open/close your zipper for a very long time the slider can again get stuck to the material, same as with a new backpack. Check section 2.
Waterproof Zipper Maintenance
Most of it was already covered above, to sum it up:
- ALWAYS rinse the zipper with fresh water after salt water use.
- Clean the zipper of sand and debris before closing it.
- Light lubrication of waterproof zippers will keep them working smoothly and prolong their life.
