If you know how to use a 110-volt, gasless MIG welder, you can build your own flat-grill hibachi from plate steel and a few other fittings. Hibachi grills taper outward from a rectangular base at a 45-degree angle to a 10- to 15-inch depth. This creates a larger cooking surface, while concentrating the heat from a smaller amount of fuel than standard grill uses. Most hibachis are intended for tabletop use.
Lay the two pieces of 10-by-21-by-1/8-inch plate steel on top of each other on your welding table, with one of the long sides facing you and all their edges and corners flush. Secure them in place using C-clamps.
Measure 3 inches from each 10-inch side, along the 21-inch side. Mark those two points using a black permanent marker. Label the point closest to the left side "A" and the point closest to the right side "B."
Draw a straight line from point "A" to the upper left corner of the sheet steel, on the side farthest from you. Repeat to draw a straight line from point "B" to the upper right corner of the side farthest from you.
Don wrap-around eye protection, ear protection and a NIOSH-approved respirator. Cut along each line using an abrasive saw blade on a right-angle grinder. Use a wire wheel to remove any burrs along the edges of the two pieces of steel plate. These are the right and left sides of your hibachi.
Don your welding helmet, gloves and full leathers.
Match the 15-inch bases of the right and left side pieces to the 15-inch edges of the 10-by-15-by-1/8-inch piece of sheet steel, which is the bottom of the hibachi. Use a horizontal fillet-weld to attach the right and left sides to the bottom. A horizontal fillet-weld joins two pieces of metal positioned at a 90-degree angle to each other.
Match the 10-inch sides to the remaining open sides of the hibachi. Use additional fillet welds to attach the side pieces.
Turn the hibachi upside down and weld the four pieces of 1-inch square, steel tubing in each corner to serve as legs.
Lay the 9-inch-long pieces of 1/2-inch square rod stock between the 21-inch-long pieces, one inch apart. Weld all pieces together to make the grill top.
Measure along the top inside edges of the 21-inch sides of the hibachi to find the center point. Weld one piece of 1-inch-by-1/2-inch-by-1/8-inch steel plate at each inside center point so that they stick above the edges by a 1/2 inch. These pieces will help keep the grill top from slipping off when it is in use.