Gun Safes Are Not Airtight | And These Reasons Are Why

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Are gun safes airtight? Strangely enough, gun safes are not airtight (for the most part)! However they do have very low air flow and that is exactly why you need a dehumidifier.

[Safe image courtesy of Fort Knox Safes]

Why aren’t gun safes airtight?

Gun safes are not completely air tight because they have holes all throughout the safe. These holes allow for some air flow throughout them as it flows from hole to hole.

Because of these, they are not waterproof, and partially why safes are not completely fireproof as well.

Where are all the hole in a safe that make it not air tight?

For being a giant steel box, it is surprising how many different places air can escape these things. Here are the main places.

  • Door seam – This is the major place that air is able to escape and move about. There are of course varying levels of air flow though. Fort Knox for example is actually relatively air tight, however Browning seems to be less so. You tend to notice the difference when you close the door. If it takes a while, and you have to push the door to close it completely, it is pretty airtight. If it clunks closed, the door isn’t super air tight.
  • Bolt Down Holes – This isn’t a super significant place that air escapes, as most safes are bolted to the ground. However these are holes, and they do exist on most safes out there.
  • Hole In Top Of Safe – Have you noticed that your safe has a hold on the top of it that has a little plastic piece in it? It’s not a defective unit, in fact it is there so chains can carry the safe throughout the warehouse during assembly. Much easier to carry it this way than by hand.
  • Dehumidifier Hole – This is almost as obvious as the door seam. Dehumidifiers actually come as a result of how little air flow safes do have. Because of the lack of airflow, any humidity that is in the air will slowly settle down onto whatever is in the safe. With a dehumidifier it will keep the air warm enough so that the humidity stays in the air, instead of on your metal firearms.
  • Wall Mounting Hole – Not many safes have this, and the ones that do tend to be cabinets. Wall mounting holes are normally found on the top of the back of the safe, and are meant to bolt into the studs of a wall. This keeps the safe from falling forward. Wall mounting holes are addition to a safe, and I sometimes wonder why higher end safes don’t have it, although I assume it’s because you need to have a dehumidifier going out the back.

Will a Palusol Seal make it airtight in a fire?

The idea of a Palusol seal is that is will expand up to eight times its size to seal off the door from fire being able to heat up the inside. 

This will make any safe about as airtight as it can be!


What we have learned to day, is that gun safes are not airtight, why they aren’t airtight, and where the air goes throughout the safe.

I have also seen that people want to make their safe even more air tight than it is designed.

Personally, I would leave it alone. Get a good dehumidifier, make sure flooding won’t affect the safe and let it be.

The more you mess with a safe, the more likely you will mess with the warranty. You don’t want that right?