Building a forge seems to be on many new knife makers minds. It is one of the repeat questions I get. Here are some of the basics:

HEAT- You need it controlled. This not only to heat what you want at the temperature you want, but also safely. I have left a few shops as they fired up the latest back yard beer can forge. Heat is controlled by fuel supplied and air. The air can be drawn in as with a venturi or forced in with a blower. The air volume and pressure can be controlled with a the blower. I use a fan speed control and waste gate valve. The fuel supplied is controlled with a pressure valve and a source valve.

Solid Container or body. Use steel, brick, ceramic, what ever works for you. Make it solid and stable. I use steel pipe, thick walled that I get at the salvage. The body must be solid and strong enough to contain the insulation and lining.

INSULATE & ISOLATE. Insulation limits the heat transfer from the inside where you want it hot, to the outside that you want not as hot. I use lining wool. Isolate means to keep what you are doing where you want it. You want hot stuff isolated from items that will burn or explode. To isolate I use refractory cements to line the inside and limit flux and hot corrosive materials from eating through the wool. The linings also help to reflect and concentrate heat. I use distance and shielding to keep heat away from the fuel lines and fuel source.

This may be one of the biggest concerns when I see a forge running. I use a long hose, and then put the propane tank as far away as possible at the rear, away from the door.

VENT: I crack the door and have a vent fan in the shop.

Any specifics will be happy to provide.

[media] http://www.youtube.c...h?v=luI-tB9UzMI [/media]

[media] http://www.youtube.com/watch?v=t2CjEcrnVGw [/media]

Enjoy,

Jim