I use propane gas and a 12 volt fan to add air. My forge is made from a wheel barrow bed, but I have seen some really nice ones made from old bar-b-que grills. A friend of mine has one that he does horse shoes with that is made from an old cast iron brake drum. I used to have a coal fired forge, but coal became too hard to get around here and what I did get was half clinkers. I tried plain old charcoal, but just could not get white hot like I wanted.

I use propane in my forge as well. The forge was built by Her Majasty's Iron Worker from Logan ,Ohio. I built the burners and finished the brick work and coating. I run 2 burners as I do a lot of welding with my forge. Still have less than $400 into it. Plenty of designs online if you look around. A good forge is only worth it's weight in the long run. Yes you can make a forge out of a wheel or a can or whatever. But for real sustained heat you need a quality built forge with a lining and brick. My forge can burn for a week without burning through, a forge that is not lined will burn through in 10 hours time with any serious heat.

Deerhunterrick, I lined the inside of my wheel barrow bed with clay from one of the Clay City pits where the bricks for the 1819 Fort Morgan were also made. Then I finished it with fifty year old fire bricks that were also made at Clay City. I needed the length of something like a wheel barrow bed to hold the bush hog blades that I wanted to sharpen. I already had my grandfathers old coal fired forge, but when I saw a forge being built on TV using a wheel barrow bed, I decided to build one of my own and it did not cost me but just a few dollars because I already had almost all the needed parts on hand.