I wanted to make something simple yet functional, portable and easily disassembleable so it doesnt’t occupy too much space when not in use.
Also the goal was not to use extra specific items, but easily obtainable ones.
Take the top of used gas tank with an angle grinder. BEFORE grinding make sure that the gas tank is empty, and unscrew the bit where it usually connects with gas hose. Flip it upside down. Grinding and poslishing or painting the inside is optional.
Get a steel pipe and saw it off at cca 7-10 cm in lenght.
Drill holes through the pipe. I went with three holes vertically at about 1 cm apart.
Weld and grind top of the pipe so it can be used as a lid and not to allow air to flow upward, but to the sides.
Tape the drilled pipe with masking tape, and put a cover on it on which the concrete won’t stick. I used a plastic pipe with similar diameter of the metal pipe.
Break the firebricks in a few dozen pieces, scoop up the powder that comes from crushing the little bits of firebrick and mix it into concrete. I used a mix of 1/2 cement and 1/2 of fine quartz sand. Arrange the firebrick pieces around in a circle and add concrete.
Let dry at least overnight so you can keep working on it, and don’t use the forge for at least a week until concrete cures.
Weld on the leg stands.
I didn’t plan this, but tought it might have happen. Since the inside surface of the gas tank is pretty smooth, the cured concrete fell out when I flipped the thing over.
If you want to avoid that, weld something thin onto the surface like nails, thin pieces of leftover iron or steel. I dealt with it so that I cut three pieces partially where the legs are and bent them inward to hold the concrete.
Now for the under part of the forge. As you can see I welded together three pipes to have the intake of the air, the ash damp and a piece which connects to airhole via thread. Sorry, I didn’t take a picture of that part.
I fabricated a part for ash damp cover. Later it will be on a hinge and spring attached to the pipe.
Here is the whole thing assembled with the threaded pipe wich connects the forge with air intake system.
Upsidedown, legs still need to be attached on which I decided to not weld or even keep together with screws since the weight of the forge and tripod system hold the thing in place.