It's summer and time for some grillin!
As luck would have it, I had access to a bunch of old bloated Sanke-style beer kegs that were no longer suitable for commercial use. Also, one thing I don't have is a barbecue. You see where this is going.
To make this barbecue you will need access to some standard machine shop tools and have the skills to use them safely. You can cut corners and use other methods but what I show here will give you the best results (except for maybe the welding, more on that in a minute).
Additionally, I have no budget and access to a shop with a prodigious scrap pile, so much of what I used in this build was determined by what I had on hand. There are definitely ways I could have made this better, but it works well with what I used.
Let's get started!
Step 1: Materials and Tools
The materials I used:
- Sanke 1/2 barrel keg
- Heavy steel door hinge
- Scrap steel stock
- Scrap aluminum plate
- Various small bolts and washers
- Store-bought grill grate
The tools I used:
- Angle grinder with cutting wheel and bonded flexible abrasive wheel
- Drill with various diameters of drill bits
- Manual shear
- Files for deburring edges, shaping wood
- MIG Welder
- Welding angle magnets
- Vice grips pliers
Step 2: Dismember the Keg
We want to make two cuts entirely around the diameter of the keg. These cuts are located in such a way as to allow the cut edges to nest inside each other and create a better air seal.
Make sure your keg is depressurized and drill a tiny hole in the side on the part that is going to be cut away, in order to ensure that the keg is empty.
Go slow and use a thin wheel on the grinder. Make sure the keg is secure or else the grinding wheel can catch in the cut and explode if the keg moves while cutting.
To remove the central tube, make some cuts through the retaining ring on top. Once the ring is in a few pieces you can pry them out with a screwdriver and pull out the central tube.
Once the keg is cut, get a file or an abrasive wheel for the grinder and remove all the burrs. The cut edges might not line up perfectly. Grab a pair of vice grip pliers and bend the edges slightly in or out as needed until the top part fits fairly snugly into the bottom part.
Step 3: Weld!
Cut some steel and weld it together as a hinge mount. I used 1.5 wide by 0.2 inch thick steel strip. The longer central bar is 4 inches long and the other two pieces are 1.5 inches long.
Use a right-angle magnet to hold the metal in position to be welded as shown. Grind welds as needed.
Clamp the mounts to the keg rim in the position shown. Line them up with features like the handles or the formed lettering on the keg to make it look good. Make sure they are level!
Weld the hinge mounts to the keg as shown. This is really difficult because the keg is thin stainless and the hinge mount is thicker mild steel. I am not a good welder, so this was a very trial-and-error process. Apparently you need a special kind of MIG wire to weld stainless. I didn't have this kind of wire, so the process was pretty difficult. When I first started i managed to burn right through the keg a few times. I turned down the voltage and the wire feed rate which helped a lot. I figured out the best way to get this to work was by starting the weld bead on the mild steel and getting a good puddle going, then kind of pushing it briefly over onto the stainless. A very inexpert rigged solution but it worked. The welds look terrible but are strong enough for this application. Grind grind grind!
Once you have the the mounts welded on, put the two halves of the keg together and line the mounts up. Clamp a hinge on to the mounts as shown. Make sure it is level!
Weld this hinge in place as shown. Grind as needed.
Step 4: Top Air Vent
In order to regulate air flow through the barbecue, vents are needed. There's already a big hole in the top of the keg from the tap valve, so we will use that for our top vent.
Get some sheet metal (I used aluminum) and cut it into a teardrop shape as shown to make a vent cover. Drill two holes in it, one for a pivot, one for a handle.
Cut the head off a 1.5 inch bolt and weld the bolt shaft into the inner rim of the tap hole as shown.
Add a bolt to the vent cover as shown for a handle. Put the vent cover over the bolt stud, add a washer, then two nuts over that to hold it all in place. Counter-tighten the nuts to keep it from unscrewing.
Step 5: Bottom Air Vent
To allow circular air flow we also need a vent on the bottom. Cut out a sheet metal rectangle and bend it to shape as shown. I used aluminum for ease of cutting but the scrap cut out of the middle of the keg would work nicely. The size is up to you, but I recommend making a much larger vent than I did.
Mark and cut the pattern shown on the lower half of the keg. Only cut out the area marked in red and drill on the red dots. The rest of the marked lines just show where the cover will be when it is open and closed.
Cut two strips of thin metal shaped as shown and drill two holes in them to line up with the bolt holes in the keg. Bolt these plates to the keg, using a nut to hold the plate away from the keg surface. This results in a gap that allows the metal strips to hold the cover in place while still allowing it to slide back and forth. The bolts on either end keep the cover from sliding off. Refer to pictures as shown.
My vent hole was only about 2 inches tall by 1.25 inches wide so it doesn't allow a lot of air flow. You may want to redesign this to have a larger hole.
Step 6: Grill Mounts
The grill mounts are very simple. I just got three long bolts and stuck them equidistant around the top rim of the bottom half of the the barbecue. The grill simply rests on top of these.
Refer to the pictures for reference.
Step 7: Getting a Handle on It
To make the handle I took a piece of thick plywood and cut it to a rough beer bottle shape using a bandsaw. I rounded out all the edges with some files and rasps. Two holes, two long carriage bolts, and a few nuts allowed me to mount it to the top half of the barbecue. I had to bend the bolts a little to be able to tighten them fully.
Step 8: Discussion
This project isn't finished!
The barbecue as shown here cooks great but it tips over when you open the lid all the way. I am planning on welding a base for it out of angle iron, adding a piece to prevent the lid from opening too wide, and giving the whole keg an effective polish. I cleaned the metal up pretty well with a light abrasive disc in a die grinder, but I would eventually like it to be very shiny.
Just a few tips about this barbecue:
- Use a chimney lighter for your charcoal! Trying to light the charcoal inside this thing is difficult, takes forever, and doesn't result in even heat.
- Burn at least two big fires in the barbecue before you use it, make sure to get it really hot. This removes any residue from oil or coatings on the metal, and builds up a protective layer of soot on the inside of the barbecue.
- This thing gets really hot, so it's easy to burn food. Practice a bit before you throw on your most expensive cuts of meat.