Recent smokeless fire pit testing got me to thinking that it might not be too hard to make one myself. Without taking anything away from the companies making smokeless fire pits, they’re fairly simple once you understand how they work.
The short story is this. I started with a 55-gallon drum, cut roughly in half horizontally, as the main body. Then I slit one of those halves vertically down the side and squeezed it to a smaller diameter to fit inside the other half; this created the double-wall construction that makes these fire pits work. After adding a bottom, I created a cap that bridged the tops of the inner and outer walls. Finally, I cut holes around the base on the outside, in the bottom inside, and around the top edge inside. It’s certainly not as pretty as those commercially available, but it works. And there’s pride in building it by hand.
How Smokeless Fire Pits Work
To understand the construction of a smokeless fire pit, you’d do well to know the engineering behind creating a flame that spews little to no smoke. These fire pits create a hot fire, pulling in a lot of air to feed it at the base. They also provide a blast of air near the top of the fire that creates a secondary combustion and help exhaust gasses burn off more completely. Ergo, less smoke.
When heat from the fire rises in the fire pit, fresh air is drawn into the space between the inner and outer walls at the bottom of the body. Some of this air directly feeds the fire at its base, while the rest of the air rises as it heats up in the space between the walls, exiting at the top, on the inside, to feed the flames. This supplies fresh air to the hot exhaust gasses, igniting them, and creating that secondary combustion. This process creates a very hot, intense fire that burns almost all the fuel, leaving very little ash.
What You’ll Need to Make a Smokeless Fire Pit
Like I did, find a steel 55-gallon drum, complete with a lid and a strap to lock it on, as well as a spare lid. Mine cost $20 at a local salvage yard, but you can also find them posted on Facebook Marketplace or Craigslist. I like to know what was in the drums I use for burn barrels, so I look for one that still has a label. If it was full of chemicals I can’t pronounce or don’t know anything about, I keep looking. In this case, the drum previously contained orange juice concentrate.
Tools:
- Metal-cutting saw
- Angle grinder
- Twisted wire wheel, and flap discs the angle grinder
- Drill
- Jigsaw with a metal-cutting blade
- Stepped drill bit
- Tape measure
- Wire feed welder
To cut the drum, I used this Makita metal-cutting circular saw, but an angle grinder with a cut-off wheel will also work. I used a twisted wire wheel on an angle grinder to remove paint and prep the metal for welding; you could also use a flap disc but that will remove some metal, so wield it lightly. And though I did my welding with a MIG wire feed welder, a flux core wire feed welder will also work. Just keep in mind that they’re not as tidy, so you’ll need to clean the slag off your welds.
Instructions
Using Your Smokeless Fire Pit For the First Time
Before you call all your friends over to show off your super cool accomplishment, you should make a fire in it to burn off any paint left on the surfaces inside. These will likely smoke off and create bad smelling—and unhealthy—fumes the first time it’s fired up. Given the drum I used was filled with orange juice concentrate, it had some coating on the inside that burned off.
So spare you friends a bad experience with your creation and break it in before you have them sitting close around it. You’ll want them to be completely impressed with how well your new smokeless fire pit works. And trust us—they will.
Brad Ford has spent most of his life using tools to fix, build, or make things. Growing up he worked on a farm, where he learned to weld, repair, and paint equipment. From the farm he went to work at a classic car dealer, repairing and servicing Rolls Royces, Bentleys, and Jaguars. Today, when he's not testing tools or writing for Popular Mechanics, he's busy keeping up with the projects at his old farmhouse in eastern Pennsylvania.
