Introduction: Build Your Own Portable or Stationary Firepit

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About: Building anything and everything in my personal shop

As we enter Fall in the US, it's a great time to get out and tackle some projects! And what better to make for the upcoming winter than your own firepit!?

Within this Instructable, I'll show you how to build two different types of firepits:

I'll start with a simple and portable version that many of you may have seen before. This style uses interlocking plates that easily assemble and disassemble. The best part, you won't even need a welder for this build!

I'll then walk through the steps for building a more complex and stationary hexagon style firepit that can be further customized with your own logos or lettering.

Step 1: Portable Fire Pit - Design and Planning

The most complicated part of this build is determining the correct geometry for the interlocking pieces. Not to worry - I've taken care of that part for you! Attached is a fully dimensioned sketch showing all five components that make up the firepit. These drawings will yield a pit with overall dimensions of 28x28x10 inches. This is a great size for portability and the perfect size for standard firewood which comes in lengths of 16 inches.

Materials:

All you will need for this job is one 4x8ft sheet of 3/16 inch thick plain steel. Using 3/16 inch thick material will yield a rigid final product that won't warp under the heat of the fire and will last a lifetime.

Tools:

I have access to a CNC plasma cutter which greatly helps to make builds like this quick and efficient. If you don't have access to a CNC plasma, you can cut these parts by hand with a straight edge and manual plasma cutter or even with a hand grinder and cutting wheel. There are some handles and vent holes which are not entirely necessary but are great additional features. If you do plan to use a cnc plasma, you can use the attached sketch as a guide to recreate the parts in a program like Fusion 360 in order to generate the necessary DXF files.

Step 2: Portable Fire Pit - Cutting Parts

Using the dimensions provided in the previous step, you can cut all parts from the 4x8ft sheet of steel. If cutting manually by hand, take some time during this step to ensure you measure and mark your components properly. If you're using a grinder with a cutting wheel, be sure to wear a full face shield. A straight edge can also help to keep your cutting disc or manual plasma cutter on the right path.

Attached are a few photos of the cnc plasma system that I used (full Instructable on the CNC Plasma build is available here! >> https://www.instructables.com/Home-Built-4x8ft-CNC...)

Once you've cut out all components, be sure to knock off any sharp corners or edges.

Step 3: Portable Fire Pit - Final Assembly

With all parts cut out and cleaned up, this pit is as easy as sliding the components together, dropping in some wood, and lighting it up!

The vent holes help to feed oxygen to the fire and the handles allow for easy repositioning.

Once you're ready to pack up, let the pit cool down and simply slide the components apart. The ashes will drop to the ground on their own.

If you're looking for a larger and more permanent firepit, read on for step by step instructions covering the build of my Hexagon Firepit complete with a removable grilling surface!

Step 4: Hexagon Firepit - Design and Planning

For this Hexagon Firepit build, you can keep it as basic as 6 solid sides or you can build in customized logos and grilling surfaces for added appeal and functionality.

I started with a CAD design. Programs like Fusion 360 are great options for working out the kinks in your design before commencing fabrication. I opted to make a hexagon pit with 14 inch tall sides and a 3 foot flat to flat width. Using your CAD modeling program, you can add logos and lettering to the side walls and have a local cnc plasma company cut these out for you (unless you have access to a cnc plasma yourself!)

Attached are a few sketches that show the exact sidewall dimensions you'll need for a 3ft wide pit. I opted to build my sidewalls from two separate sections of 3/16 inch thick steel plate. I used my homemade hydraulic press brake to help me make the bends on each half (full Instructable on the Press Brake is available here! >> https://www.instructables.com/Building-a-40-Ton-Hy...). The attached sketch shows exactly where you will need to make the bends (at 20-11/16 inches) and the required angle (120 degrees).

If you don't have access to a press brake, you can cut the side walls out as 6 separate pieces and simply weld them together.

I opted to add in a bottom plate and grilling surface. The grilling surface is designed to swing away or remove completely from the pit. The bottom plate helps to keep your fire elevated for better air flow.

Materials:

  • One sheet of 4x8ft 3/16 inch thick plain steel
  • 5/8 inch all thread and nuts for the grilling surface
  • Black high heat paint

Step 5: Hexagon Firepit - Cutting Parts

Attached are some photos of the CNC Plasma cut parts along with an image of the components nested onto a single 4x8ft sheet of material.

If you don't have access to a CNC Plasma, you can hand cut a design using a manual plasma cutter or just leave your sidewalls solid.

You'll also notice a few small brackets and angles. These serve a few different purposes:

  • Brackets to raise the bottom plate away from ground level
  • Brackets for the grilling surface's swing away hinge
  • Angle brackets for use as a guide when bending the sidewalls and welding together the two halves

Step 6: Hexagon Firepit - Fabrication and Assembly

With all parts cut out and cleaned up, you can begin marking, bending, and welding it all together.

Starting with the two side walls, draw vertical lines at 20-11/16 inches. These lines will serve as the bending locations. Make two 120 degree bends on each sidewall to create the two halves of your hexagon.

If you're working with 6 separate sides, you simply need to weld all sides together with 120 degree joints.

I used a couple bar clamps to keep the assembly rigid while welding.

I also cut out and bent up the grilling plate - an optional feature.

Step 7: Hexagon Firepit - Coating and Final Assembly

I used a high heat black paint to coat all portions of the pit except for the grilling surface. It is especially important to ensure you coat the intricate areas of any symbols or designs that you cut into the sidewalls.

For corrosion resistance, I used 304 stainless steel expanded metal for the grilling platform.

In total, this pit weights approximately 170 pounds. I spent a couple days designing and a couple days building it (part time).

Hopefully these steps will assist you in fabricating your own portable or stationary firepit! Thanks for checking out my build!