The Gravity Bong: Step-By-Step

Whether you call it a GB, geebie, geeb, yoin, buckie, or a bucket bong, a gravity bong is an impressive DIY instrument in cannabis engineering. There are many benefits to using a gravity bong. It’s among the most cost-effective and easy ways to get yourself elevated without using a traditional glass piece, blunt, or joint.

Despite being decades old, gravity bongs are relatively low on most people’s radar when it comes to choosing a way of consumption. So, what exactly is a gravity bong? How does it work? Are they easy to make? What do I need to make one? Read on to find out. 

A gravity bong’s name comes from how it works, though a more appropriate name might be a vacuum bong. These smoking devices work by creating a vacuum between two chambers with water (or another viable alternative) as a sealant in the middle.

First, a larger receptacle (typically a plastic bottle with the top cut off) is filled with water with its open end pointing upwards, and a smaller container (usually a smaller plastic bottle with the bottom cut off and an opening for the cap at the top) is then submerged in the larger bottle. A bowl with a small opening at the bottom is attached to the smaller bottle where the cap would be, filled with cannabis and lit. As you pull the top chamber out of the water, it creates negative air pressure between the two chambers that pulls air through the bowl, filling the space between smoke.

Gravity is what keeps the water in place at the bottom for you to pull against to create the vacuum. However, there are many variations on this theme, such as a waterfall bong, all of which include creating a vacuum to pull and store the smoke similar to an accordion or a fireplace bellows. This is also how your lungs work: muscles pull our lungs outward and air rushes to fill the vacuum.

Once the vacuum is filled with cannabis smoke the bowl is removed, and the consumer can inhale the hit. Normal inhalation will pull the smoke out at a comfortable pace (and draw water up), but if you push down, the smoke will be forced out, assisting the hit. Be aware: because there is no air inside the vacuum to mix with, the resulting smoke is highly concentrated, and will deliver a powerful hit, which can often be intense for newer smokers, or those with a lower tolerance.

There are companies out there that make gravity bongs out of glass, heavy-duty plastic —even types of vaporizers that can act as a gravity bong. But we want to make ours at home, right? If so, all you need is the following:

• Plastic bottle with a small opening
• A plastic container that is larger than your bottle
• Scissors 
• Toothpick
• Down stem and/or bowl, a Pipe Screen or Metal Bowl, or tin foil

*A note about materials: The risks of using plastics as smoking devices, especially plastics not intended to be used as smoking devices, are unknown. Burning or even just heating plastic can cause chemical changes that may release harmful substances (especially if the flame of your lighter touches it). Furthermore, there are mixed sentiments regarding igniting something on aluminum foil. PotGuide is in no way giving health or safety advice in the article, proceed at your own risk.

• Pierce the smaller plastic bottle with the scissors no more than 2 inches from the bottom. Then insert the scissors into the incision to cut the around the bottle completely and discard the bottom. 

• There are a few ways to form the bowl. The ideal method is to use a glass bowl with enough of a neck to sit inside the bottle top. (see photo). These can be purchased at most headshops as standalone items. You’ll start by making a hole in the bottle top first. Keep in mind the size of your bowl or insert as you form the hole. A pair of kitchen scissors should do the trick (or a drill/dremmel tool if you’re extra handy), but be extra careful to not slip or cut yourself. You’ll also want to ensure that the cap can still be comfortably screwed on and off the bottle.

• Once you’ve made the hole in the bottle top, insert the bowl and screw the top back onto the bottle.
• If you don’t have a bowl or similar receptacle, the ”traditional” way to make the bowl is with aluminum foil. Take the cap off the bottle and cover the whole mouthpiece with aluminum foil, pressing firmly to make sure it stays in place. Then, use the toothpick to create 3 to 4 tiny holes in the tin foil. Your bud could fall into the bong if you make too many holes or make them too big so it is very important to be mindful of this.
• Next, you’ll be filling your larger plastic container with the liquid of your choice, leaving an inch or two between the water and the rim. This larger container is usually just bucket or larger bottle. For example, if you’re using a water bottle for the top half, a 2-liter soda bottle can form the lower half. To prep it, you’ll cut off the top using scissors the same way you cut the bottom off of the top chamber. If you’re using a bucket, simply fill the bucket.

• Place the smaller container inside the larger one

• Add small amounts of your ground cannabis on top of the bowl

• Pull the smaller chamber up slowly as you light the bowl. Through the power of science, a vacuum will form between the water and the neck, which captures the smoke.
• Once the chamber is loaded and you’re ready to inhale, remove the bottle cap or bowl, and breathe in the smoke from the top of the bottle. As mentioned, if you press down on the top bottle, you can create a small jet stream, to either assist your hit, or let you take the hit without putting your mouth on the bottle opening.

PotGuide Tips:

• If you choose to use a larger plastic bottle than your original one, such as a 2-liter, cut off the neck of that bottle so the rim is the same width as the smaller bottle.
• If you’re pressing down on the bottle top to create a stream to inhale, suck up the smoke as it comes out, sort of similar to how you would drink from a straw.
• If you’re not careful, the smoke that comes from a gravity bong can make you choke since it is so concentrated. If this is the case, you can make the hit less harsh by adding ice to the liquid in the larger chamber.
• On the other hand, If you want to have a more intense experience, you can also substitute your flower with hash oil.

Because a gravity bong’s hit can be more powerful than most bongs, take smaller hits than you’re used to, especially if you do not partake in cannabis regularly. But if you’re looking for a simple, inexpensive way to send yourself to another planet for a while, a gravity bong may be the right fit for you.

What do you love about gravity bongs? Have any cool tips to make one? Share in the comments!