
In the world of cigar humidors, there are quite a lot of cheap, medium-priced, and expensive options for you to choose from. One of the main differences between cheaper and premium boxes is that the budget humidors hardly manage to keep their relative humidity in check. In most cases, this is due to air leaks. In this article, we will learn how to tell if a cigar humidor is sealed properly. Moreover, we will also take a look at the possible solutions you can try out in order to fix that!
Two of the most commonly used methods to diagnose a leak that we will discuss here are:
- The dollar bill test
- The flashlight test
If you also want to get a new humidor that will have great leak-free build quality, make sure you check out my guide on some of the best cigar humidors for this year! Before we get into all the diagnostics and solutions, let’s answer the most important questions here…
Why do Humidors Leak?
Humidor leaks can either happen out of the box or appear after a prolonged period of using them. If you can’t achieve ideal temperature and moisture control even after seasoning the humidor, you almost definitely have a leak going on. One of the most common reasons is the glass lid on most modern humidors. They usually leak when there is a change in ambient temperature or just from old age. Most cheaper glass lid humidors leak even when they are brand new, which is why most people simply replace the glass with a thicker and sturdier plexiglass panel.
Another reason cigar humidors might be leaking is because there are defects from the factory. Some lids can be uneven or have rough edges, preventing them from sealing properly upon closing. Most lids nowadays have a magnetic mechanism which can also be slightly off. To counter that, manufacturers use a combination of a magnetic lid seal plus a wooden lip that goes into the body of the humidor, further preventing air leaks.
How to Diagnose the Leak

As I mentioned earlier, there are two major ways you can see if your humidor is not sealing properly. These are the dollar bill method and the flashlight method. Let’s discuss those in a bit more detail now…
The Dollar Bill Method
The dollar bill method of diagnosing humidor leak is one of the simplest ways to test such issues. However, it doesn’t work as well on smaller travel humidors or acrylic humidor boxes. The method goes as follows:
- Take any dollar bill and fold it as flat as you can
- Insert the bill between the humidor and its lid
- Shut the lid down
- If the bill is easy to pull away from the humidor, then you most likely have an issue with the sealing
If the bill doesn’t move, it means that the seal closes tightly and the problem stems from another region of the box. Sometimes humidors have locks in place or glass lids. These can also cause air leaks. With this bill method, you can also move the bill around the humidor and see if there are any inconsistencies in the closing of the lid. Some boxes can have poor quality control from the factory. These will most likely have warped lids that have areas from which moisture (and air) can leak out.
The Flashlight Method
The flashlight method of finding air leaks in your humidor is pretty self-explanatory. You need to be in a very dark room for this test to truly work. It can be used both to diagnose issues with the glass lid or with inconsistencies in the way the humidor shuts. Turn the lights off in the room and start going around the humidor with the flashlight. The glass top will help you see if any light goes past the closed lid. When you are done checking that, you can also shine into the humidor from above and see if the seam of the lid lets some light out.
Now that we’ve made sure that there is a leak in our box, let’s see how we can fix that!
How to Fix a Humidor Leak
You can do a few things in other to fix the air leak on your humidor. Some people prefer using beeswax to make the humidor seal better. This method doesn’t have any huge downsides to it, although it might affect the look and feel of your humidor. It will feel different when it close and there might be some wax leftovers falling inside and outside of the box. Either way, wax is one of the universally good ways to seal things shut.
Another very good way to seal cracks in your humidor, either in the glass lid or the wooden body, is by using silicone. Now, since most industrial-grade silicone will have unpleasant chemical scents to it, you will have to use food-grade one. These are odorless and won’t affect your cigars in any way down the road. Start by removing all the cigars from the box. You can either place them in another humidor if you have one or use a zip-lock back and a Boveda hydration pack. That should take care of the temporary storage issue.
Now that the humidor is empty, locate the crack and carefully fill it with the silicone you’ve gotten. Make sure that there is no excess silicone dripping from the crack. Most cracks happen on the inside, so your exterior will be likely spared. After you’re done, leave the humidor open for a few days so that the silicone can tighten up. If there are any unpleasant scents, that will also take care of them. After that, you can season your box once again (optional) and return your cigars in it. Make sure you test whether the humidor holds its humidity after you’re done fixing the leak.
If you’ve just gotten your humidor box and want to make sure that everything is set up and seasoned correctly, make sure you read my detailed step-by-step guide on that topic!
Frequently Asked Questions
How do I make my humidor seal better?
One of the best ways to make your humidor box seal better is by applying colorless and tasteless beeswax. This will reinforce the seal and remove any uneven edges on the box’s lid. However, wax has some obvious drawbacks that might make you consider another method. Oftentimes, humidors leak from their glass lid. Try replacing that with a thicker and better-made plexiglass lid.
Should cigar humidors be completely airtight?
While cigar humidors should pretty much keep their internal air moisture and temperature constant, they should also never be fully airtight. This is why most models are built in such a way that they let out a little bit of air out. This is done in order to release the excess moisture. However, in some cases, it might release too much of its moisture, resulting in a dried-out interior.
How long is a sealed cigar good for?
Cigars sealed in their cellophane wrappers don’t tend to last more than 30 days when they are kept outside of a proper humidor. Inside the humidor, however, they can last practically indefinitely if you keep the conditions stable. Most beginners think that cello-wrapped cigars can last much longer which is one of the main reasons for cigars drying out.
Can you keep your cigars in the fridge?
While the overall lower temperatures of a fridge won’t damage the cigars, the lower humidity will. In general, fridges have a much lower RH (relative humidity) compared to normal humidor boxes. It generally is around 40-45% RH which can be devastating for a cigar. This is why there are special cigar humidor coolers that keep the temperature and moisture at the exact levels they need to stay at.
How long does it take for a humidor to completely dry out?
If, for some reason, you want to “reset” your humidor’s humidity levels before seasoning it, you have to dry it out properly. To completely dry out a humidor, you have to place it open in a warm rood. The room can be also air-conditioned. Normally, it won’t take more than 20-30 hours for the humidor to lose most of the moisture it has been holding in its walls.
Final Words
Learning how to tell if a cigar humidor is sealed properly is not necessarily that hard, especially if you use one of the two methods we discussed here. If you don’t have a dollar bill with you, you can use any piece of paper for the dollar bill test. Both it and the flashlight tests are pretty good at discovering small leaks and inconsistencies along the ridges of the humidor’s lid. Sometimes, the air leak can also come from the glass on top of the lid, so make sure you replace that if nothing else worked on your box!