Introduction: Dumpster Fire Pit (easy Welding Project)
In honor of the year 2020, I decided to build a fire pit shaped like a dumpster. It turned out to be a pretty quick and easy project, even for a novice welder like myself.
Quickly I want to say that if you're going to be welding and cutting, please take the time to learn how to safely do these things before attempting the project.
NOTE: I included a build video with the guide that might fill in any gaps or answer any specific questions you have about it's construction, so please have a look at that first before beginning (its short)
So if you want one of your own, here's what you'll need:
- A Welder: really just a way to stick metal together, whether its a stick welder, a MIG welder, flux core, or TIG (ooh you fancy), you're gonna need one for this build.
- Angle Grinder: or really any tool you have to safely and reliably cut steel. I chose and angle grinder with a diamond wheel. You may choose an abrasive wheel, or a metal cutting chop saw, or a metal cutting band saw, or something else. So long as you are comfortable using it to cut both tube and sheet steel, it'll work.
- Mallet: I went with a rubber mallet, this is to help "persuade" any parts of the project that don't want to cooperate.
- Clamps: I prefer to use medium sized C clamps for metalworking, along with a few pistol-grip quick clamps, but you use what you want, just know you're gonna have to clamp some stuff with a strong hold, and spring clamps wont cut it alone.
- Measuring Tape: or a ruler, I suppose. Really whatever you want to use that can measure at least 36" and has 1/8" markings on it.
- Square: I used an aluminum speed square, but anything that will tell you whether or not your angles are right.
- 3/4" Square Tube Steel: at LEAST 144" (i'd get closer to 200" just in case) of it. It's almost always available as mild steel, but make sure that you get a type that your tools can cut and that your welder can weld.
- 1 1/4" Square Tube Steel: At LEAST 16" worth, but to be safe i'd get 24"
- 1" Angle Steel: AT LEAST 60" worth. Might wanna get 75" or so just to be sure.
- 1/16th" (16 gauge) Sheet Steel: Again, make sure you get something that you can cut and weld with your tools. You'll want this to be AT LEAST 20" by AT LEAST 75", but give yourself some wiggle room if you feel like you need it (you will)
- Expanded Steel: The box store sells a 24" x 24" sheet that's perfect for this project, but you use whatever you prefer. Make sure you have enough to make two 24" x 14" panels.
- 1/8th" Steel Rod: Once again, something you can cut and weld. Youll need at LEAST 72" of this, but give yourself some wiggle room and get about 96"
- Hinges x2: Something steel, and about 1-2" wide. Crappy cabinet hinges are best, but a piano hinge will do also.
- Small Casters: I used some one-directional, 1" plastic casters with a metal base
- Wire Brush, Abrasive, or Sandpaper: Really just something that can get any paint, rust, or dirt off of your parts before welding.
- Acetone - for removing any stickers, labels, or oils off of the steel before you weld it. Grab an old cloth while you're at it.
(OPTIONAL) Metal Brake: for bending sheet steel
Step 1: Gather, Measure, Clean, and Cut Your Material
Cut your steel rod and tube to the following lengths:
- 3/4" Square Tube Steel: 5 x 12" lengths, 4 x 24" lengths
- 1 1/4" Square Tube Steel: 2 x 8" lengths
- 1" Angle Steel: 4 x 15" lengths
- Expanded Steel: 24" x 14" panel with 2"x 2" square notches cut out of the corners (bottom) and 24" x 14" panel (top). These can be trimmed later if needed.
- 1/16th" Sheet Steel: 17" x 75" panel (can be trimmed later)
- 1/8th" Steel Rod: 2 x 24" lengths, 2 x 14" lengths (cut these a little bit long, as you can trim them down later)
Step 2: Weld Together Your Base and Top
- Using the 3/4" Square Tube Steel, arrange your base rectangle so that your 12" pieces, sit inside of your 24" pieces, as shown in the pictures above. Use your speed square to make sure the angles are right.
- Weld together starting with tack welds on each corner, then going back and filling in the rest. Be careful not to overheat the steel too much or it'll warp.
(Note on bends, dents, dings, and twists: So long as they're not too extreme or compromising to the structure, some imperfections are fine. We are, after all, making a dumpster fire)
- Repeat the process with the rest of the 3/4" Square Tube Steel to end up with 2 identical rectangles.
Step 3: Place and Weld the Risers
- Starting with one of your rectangles lying flat, weld one of your 15" lengths of 1" Angle Steel to the interior of one of the corners, as shown, perpendicular to the rectangle with the corners matching to the angle of the steel.
- The bottom edge of the angle steel should be flush with the bottom face of the tube steel.
- repeat this for all four corners
Step 4: Position and Weld the Top Rectangle
- Slide the other rectangle over the top of the welded risers and clamp so that the top edge of the angle steel is flush with the top face of the tube steel.
- Check that all angles are as right as can be, and that everything is as straight and level as desired.
- Weld the top rectangle to the risers the same way you did the base.
Step 5: Prep Your Sheet Steel and Bend It to Shape
- Since I used an old bench top for my sheet steel, I was able to utilize the existing bent edge for the top of my fire pit. I also, however, had to notch out a few parts so that the frame would nest inside of that bend.
-I would suggest that you use your completed box frame to figure out where you'll need to bend the sheet steel to get it around the sides. Use one of the long sides as your starting point.
- If you have a metal brake, this is easy, just fold the sheet steel at right angles to match the exterior dimensions of your welded rectangles. If you, like me, don't have a metal brake, then lay your frame on the sheet steel, allowing 1" to protrude above and below the short side, as a lip for the top and bottom.
- Clamp your frame to the sheet steel, lay the sheet flat on your bench or work surface, and using the frame, bend upwards at your desired bend location, using the frame as a fulcrum, as shown.
- Repeat this all the way around, using a mallet if needed to bang the sheet into right angles (and it leaves some cool dings in the steel, making look more like a crappy dumpster)
- On your 1" top lip, notch the corners so you can hammer the sheet steel down over the top of the frame, hiding it. Make either a straight cut and fold the steel over itself, or make a 45 degree cut so that it miters when folded (as shown above) You'll hammer this part down AFTER you weld the sheet steel to the frame. If you're using a metal brake, you can make the bends with that BEFORE you weld it to the frame.
Step 6: Weld the Sheet Steel to the Frame
- Using small tack welds, attach the sheet steel to the frame, making sure you have 1" of overhang at the top and bottom of the frame.
- Hammer down with your mallet, or otherwise bend, the top 1" of sheet steel at a right angle over the tube steel frame, and weld in place. The notches you cut earlier should make this easier.
Step 7: Prep Your Bottom and Weld It in Place
- take your notched expanded steel bottom panel, and dry fit it into the inside bottom of the frame. It SHOULD sit on all 4 sides of the bottom frame rectangle with the angle steel risers fitting into the notches. If it doesn't, make whatever adjustments are necessary so that it does.
- Weld the expanded steel panel to the frame wherever it touches.
- from the bottom, take your last piece of 3/4" Tube Steel (previously cut to 12") and weld it across the middle of the frame, flush to the frame. This will act as a crossbrace
- Weld the expanded steel bottom panel to the crossbrace.
Step 8: Build and Attach the Top Panel
- Take your un-notched, expanded steel panel and lay it out o top of your box, making sure it cover the entire thing, edge to edge.
- Weld your 1/8th" steel rod around the outside of the panel, making a frame, and trimming away any excess.
- take your hinge and cut along one side, about 1/8th" from the pins, as shown.
- weld the cut part of the hinge to the long edge of the top panel, as shown. Lay it so the uncut portion of the hinge folds over the top to what will be the BACK of the firepit.
- weld the uncut portion of the hinge to the back of the firepit, as pictured.
- repeat the last three steps for the other hinge, making sure to align it along the same edge as the first one.
Step 9: Add Your Casters
- flip over the box and place the casters at the corners of the frame, as shown, taking care to align them properly so the box will roll if needed.
- weld the metal bracket on the casters to the frame, being careful not to melt the sheel or accidentally weld the caster into a frozen position.
- if the casters dont stick out further than your 1" bottom lip of sheet steel, mark and trim the sheet steel around the bottom of the firepit so that they do.
Step 10: Weld the "Lifting Tubes"
- dumpsters have slots on the sides where dumptruck can come and lift them up for disposal. We will use our two sections of 1 1/4" Square Tube Steel to mimic these.
-Make sure the firepit is right side up
- Position the tube horizontally about 8" from the bottom of the box on the short side, parallele with the ground, as pictured. (I used a bit of leftover square tube as a spacer for consistency and to help hold it in place)
- Tack and then weld the tube into place.
- Repeat on the opposite side.
Step 11: Decorate Your Dumpster
I added a little bit of graffiti that said "F 2020," for obvious reasons. You can patina, or paint, or mark up your version however you want, but keep in mind that the heat will affect most of this. My paint burned almost all the way off in a few spots after one burn. You CAN use heat resistant paint, according to its instructions, if you want a permanent layer of protection. I prefer to let my dumpster rot in the weather, as it feels more authentic.
Step 12: Enjoy Your New Fire Pit!
Light a fire, kick back, and enjoy the warmth coming off of your very own, personal dumpster fire.
Thanks for checking out this guide, and if there's anything I may have missed or mixed up, please let me know so I can fix or include it.