How to Make a Blacksmithing Forge

Blacksmithing is enjoying a resurgence with hobbyists due to new propane-based forge designs.

There are many ways to make a forge for blacksmithing, but you have to design it with certain key considerations in mind, particularly the internal size of the forge and the size and number of burners required to get your metal up to forging temperature. Additionally, if you will be forging long pieces of metal, then your forge will have to be designed to accomodate these items. The most cost-efficient and convenient configuration for a blacksmithing forge is a propane-fueled unit made from a metal frame securing some refractory brick.

Things You'll Need

• Pen and paper
• Tape measure
• Refractory brick
• Angle iron
• Acetylene torch or angle grinder or hacksaw
• Welder
• Plate steel
• Clamps
• 1" pipe
• Drill
• Drill bits
• Tap
• 3 Hex-head bolts
• Flat stock
• Paddle bit
• One or more propane burners
• Teflon tape
• Soapy water
• Propane

Instructions

Designing the Forge

1. Purchase the refractory brick that you will use to line your forge.

2. 

   Do alot of figuring on paper before you start cutting brick or metal.

   Make a detailed drawing of your forge with dimensions, and use the dimensions of your refractory brick to help you determine both the chamber size and the frame size of your forge.

3. Build a mock-up of your forge, using your bricks, to work out the measurements of your frame.

Construct the Frame

1. 

   The metal frame of your forge needs to be sturdy to keep your firebrick in place.

   Cut your angle iron to length (using the measurements derived from the mock-up).

2. Weld the angle iron into a box shape.

3. Place a piece of plate steel in the bottom of your forge.

4. Weld a short piece of 1-inch tubing to one end of the angle iron section and weld the other end to the forge frame to hold the burner in place; drill and tap three holes in the tubing, then install the screws to secure the burner.

Install the Firebrick

1. Place the forge frame on a surface that can withstand high temperatures.

2. Lay the firebrick in the bottom of the forge frame, then stack it on two sides for the walls.

3. Place the bricks for the roof/ceiling on the tops of the two walls (if your frame was built with tight tolerances, the bricks will sit fairly straight without any support underneath the center-line; if it is somewhat loose, shim the difference with some flat stock).

4. Use a paddle bit and screw gun to bore a hole for the burner.

Testing the Unit

1. Install your burner, then attach the hose and regulator using teflon tape to seal the threads, perform the soapy water test for leaks, then light the burner.

2. Note any places where heat escapes and adjust the bricks accordingly.

3. Forge metal.

Tips & Warnings

• This type of forge allows for easy reconditioning when the bricks need replacement.

• Use the dimensions of your refractory brick as a standard for the dimensions of the chamber and the frame of the forge.

• Design your burner holder to have the burner enter the chamber from the top and at an angle to control the circulation of the heat inside the chamber.

• To increase the heat retention qualities of this forge, stack firebrick in front of the openings.

• Observe standard precautions when using your cutting torch and your welder.

• Refractory brick contains silica and other minerals that can be hazardous to your health if inhaled. Use the proper safety equipment when working with these bricks.

• This forge design uses oxygen drawn from the atmosphere through the three openings. Do not block all of the openings during operation.

References

• Popsci.com Propane Forge Project
• "Gas Burners for Forges, Furnaces & Kilns"; Michael Porter; 2004

Resources

• Backyard Gas Foundry & Forge
• Sheffield Pottery for refractory brick.
• The T-Rex Burner at Hybridburners.com
• Zoeller Forge
• Reil's Modified Burner Blueprint