If you are a frequent/experienced cannabis smoker, then you have surely tried out a bong, pipe, bubbler, steamroller or other glass pieces before. If not, then what do you prefer to use when smoking? Maybe you like to roll up a blunt or joint. Or, maybe you prefer dabbing. That’s cool too, but in this post we will be focusing on using a glass piece.
If you do like to use glass pieces or simply have used a piece at least once, then you know that in order to take a hit, you must cover a hole. This hole is typically next to the bowl of weed, and is connected to it. It is not the mouthpiece, however, it is a separate hole that must be covered usually by your finger. When the weed is being sparked, you cover the hole and inhale through the mouthpiece. Then, you continue to cover the hole while you inhale in order to generate more smoke. When you are ready to clear the smoke, you release the hole and inhale it all up. But why do we cover that hole? Is it necessary? I mean, most pieces come with that hole, so it must be necessary. Let’s figure out why we need that hole and the science behind it.
How It Works
The hole that we are talking about is called a “carb” in the cannabis community. This title is short for the word carburetor, and no, not the same as a carburetor in a car. According to YourDictionary, a carburetor (in weed terms) is “a small hole in the side of a bong or water pipe that is stopped with a finger and then quickly unstopped as a person is inhaling to force smoke out of the drawing end of the pipe.” So, as stated above, a carb is a hole that is covered when taking a hit. In many bongs, the carb is represented by a bowl that does not need to be covered, only pulled out when clearing a hit.
In the picture below, you can see a carb on a glass bubbler:

For those of you who have never used a carb, or struggle to do so, here are step-by-step instructions on how to properly do so:
- Put your mouth on the mouthpiece and cover the carb with your finger
- Light the weed in the bowl while still covering the carb and inhaling through the mouthpiece
- Remove lighter, continue to cover carb and inhale until you have a big enough hit (for yourself)
- To clear it, uncover the carb and quickly inhale in the smoke
That’s it! Doesn’t seem that difficult, right? It’s not, and even the dumbest stoner can accomplish it. During step 3, you can choose how big your hit will be. The longer you cover the carb and inhale, the bigger the hit will be. But be careful, as a beginning smoker can easily take too big of a hit without noticing (you don’t want to get too high).
Why Do We Do It?
So you know how to use a carb and all, but why do we have to do it? What is the science behind covering a carb in order to take a decent to big sized hit? While it may be simple to some, others have a harder time comprehending it, which is why it is broken down below.
A carb in a piece essentially allows airflow through the piece to be halted, allowing for air to only pass through one way: the bowl where the smoke is coming from. So, when the carb is covered, only smoke may enter through the mouthpiece. When you release the carb, air will rush in and combine with the smoke, effectively reducing the amount of smoke that is produced, but allowing what smoke did make it to quickly enter your mouth.
Without proper airflow, the smoke will pass through, but at a very slow rate. Air is still able to seep through the smoke, which is how the smoke is able to travel at all. But when the carb is uncovered, much more air can enter and allow the slow moving smoke to speed up. This is how clearing the smoke works. A carb pretty much creates a vacuum for the smoke. By pausing air flow, more smoke can be created. When the airflow is resumed, less smoke is created, but the smoke that is sitting in the piece will quickly enter your mouth. Make sense?
What If We Didn’t?
Now, you may be thinking: “so a carb blocks off air so that more smoke can be created; what if we just never had a carb?” Would a piece work without a carb at all?
Well, think about what was stated above. When the carb is covered, airflow is blocked to allow more smoke to be created. Then, the uncovered carb will speed air towards the smoke allowing it all to enter your mouth. However, without that carb, airflow can never be added. If you want to get a demonstration of this for yourself, try smoking out of your glass piece without ever uncovering the carb.
Doesn’t work very well, right? The smoke will seem to move slower and slower until it seems to be sitting still, even though you are inhaling. You need more airflow. That’s the only thing to it. I bet if you try the demonstration out, you end up giving up and releasing the carb to inhale all of that smoke.
There are actual pieces that are made without any sort of carb or additional airflow. This pieces are tricky, however, and typically cheap and don’t last long. How do they work? Well, they work just as you think they would: barely. The best way to use one of these pieces is to sell it and buy one with a carb. I’m kidding (partially). A good way to use these pieces is to use less in your bowls, to allow more space for air to enter. You could try taking snappers, leaving half of the bowl exposed to air. While this works, it forces you to use smaller bowls compared to a regular piece with a carb. If you are microdosing, then this may not be an issue. But for the average stoner, just switch to using a carb.
Do you now understand why we must cover that hole to take a hit? If not, drop a comment down below or message us on our Contact page and we can clear things up! Thanks for reading, and happy smoking!