This is my version 2 forge I made specifically for making my knife (instructaable coming late june). my version one was not worthy if an instructable. I've only done this once before and my last one was terrible, so let me know if there are any problems.

Step 1: What You Need

You will need

Post hole digger (optional)
Shovel (not optional)
6" duct pipe 90º elbow (not optional either)
6"-4'' reducer
Some land you can dig up
A leaf blower or some other powerful fan

Step 2: Dig Yo Hole

Dig a hole about one foot deep at the forge end and 6" deep at the other end. assemble your pipes and put them in to check your depth.

Step 3: Cover It Up

Take a shovel and block the end of the pipe like in the picture. Once you do that cover the tubes up with dirt. Stick the blower in the end of the tube, put some hot coals in the thing and then turn the blower on. (Caution do not pick up the coals, even if they look very cool.) Lots of sparks go flying when you turn it on.