When shopping for a propane regulator and fittings, make sure to get a tank connection that looks like the one attached to the regulator in the picture. The new-style connection, pictured sitting next to the regulator, has a safety feature built in that shuts down the propane flow if it thinks you have a massive gas leak. This is good for BBQ grills, but unfortunately for us, this burner behaves a lot like a massive gas leak. The older style connection won't trouble you with that "safety" feature.
The forge itself is basically a box made of refractory material and the steel needed to contain and support it. In my forge, I used refractory brick purchased from a friend with a ceramics supply and kiln repair business. If there is no such business near you, you can order a variety of refractory material.
As you can see in the pictures, I built a very simple and small forge. I wasn't sure how much forging I actually planned to do, and I didn't want to go overboard. This size was adequate for everything I did, even though a larger forge would have been convenient at times. Were I to do it again, I would build a forge that was longer, with two burners to keep it uniformly heated, and wider as well. This forge's width was dictated by the length of my brick. A wider design would call for either different refractory material, or an arch-like arrangement of the bricks to span the distance. Also, while I left the back of my forge open to accommodate longer work pieces, I would close all but a window in the back of a larger forge. I would probably also build a door for the front. This forge loses a lot of heat through the front and back. I address this partly by piling extra refractory bricks in front of and behind the forge when I am working.
Refractory brick is easy to work with in that it is very easy to cut and drill. It's hard to work with in that it is brittle. Buy a bit more material than your forge design will actually require on the assumption that you will destroy some of it.
To construct the forge, come up with a design that works for your expected needs. Plan the layout of the refractory material you have chosen. Then design an outer support of steel that will keep that refractory material in place once assembled. On the inside, your layout of refractory material must support itself. As you can see in my design, I went with a very simple arrangement of the bricks that is held in by a minimal frame of angle. Your design will depend on the size and shape you've chosen for your forge.
Finally, you need to combine your burner or burners with the forge you've built. Choose a central location for the burners and determine how they will attach to the frame of the forge. In my design, a piece of flat bar bent into a U shape clamps the 3/4" black pipe of the burner to the forge frame. (There are U clamps available for black pipe like this 3/4" pipe, but I didn't have one on hand when I was building the forge.)
A hole needs to be cut where the end of the burner passes through the refractory material. The fire brick is so soft that I was able to easily use a hole saw by hand to make this hole.
Once everything is assembled, you're ready to fire up the forge and begin forging. If you find that it captures your attention, you can learn more about the art in many places. One good place to start is Anvil Fire and another is ABANA.
We'd like to see your forge and things that you've forged. Add the pictures to the PopSci Pool on Flickr.
A Note About Safety:
Please pay attention to safety. The forge is HOT. The metal coming out of the forge will be HOT. Keep in mind that, while we've shown you have to build a forge here, no information has been provided as to how to forge. You must do your research and learn these techniques before you jump in. Keep in mind that this forge burns propane and produces waste gasses including Carbon Monoxide. Only use the forge outside or in a very well ventilated indoor space. Use your common sense and always wear eye protection.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.