For centuries, blacksmiths have been heating metals and hammering them to create objects. Wood, coal, or bituminous coal is used to heat the forge. For a modern-day hobbyist, a simple brazier and bellows are sufficient to reach adequate temperatures to create small objects.
Steps
Step 1. Determine the characteristics of the metal you will be processing
Iron is forged between 650 and 1400 ° C, while brass and bronze are forged at lower temperatures.
Step 2. Choose a fuel for your forge
Natural gas, propane, or LPG are available at many retailers, but if you want to heat your forge the old-fashioned way, coal is best.
Step 3. Design a forge sized to fit the projects you intend to make
At a hobby level, it doesn't need to be too big. If you want to forge swords or other long weapons, you may need a deeper brazier. To create very large and heavy objects the ideal is to have a lifting system above the forge, but here we will deal with a smaller furnace, suitable for working with steel.
Step 4. Choose the right place to build your forge
If you need to use it for demanding projects quite frequently, you may want to place it inside a shed or building, but doing so will have to channel the excessive heat out of the work area. We stay on a hobbyist level by placing our forge outdoors.
Step 5. Build a concrete foundation
A 50 x 70cm base will do. Put reinforcement bars to reinforce the concrete and pour. Level and smooth the concrete.
Step 6. Lay a rectangle of brick about 60 cm high
Leave an opening in the back to remove the ashes. The opening must be approximately 30 x 30 cm. Later you can build a metal door, but now it doesn't matter.
Step 7. Create another opening for the air duct
You can do it on the side or in the front. A 10 cm diameter iron pipe is sufficient for this project. You can use a bellows or an electric fan to provide the forge with the necessary ventilation.
Step 8. Place a metal plate over the brick wall
This should be about 7.5 - 10 cm lower in the center. It can be in 12 or 16 stainless steel, or in 6 mm cold rolled steel. It must be strong enough to support the refractory lining. A hole will be made on the bottom for air circulation.
Step 9. Lay the furnace floor using firebricks or soapstone
Mix the mortar with fireclay to increase its resistance to high temperatures. The bricks will protect the metal brazier from heat. The sides of the furnace, always to be built using refractory bricks and mortar, will have to support the tools you will use to handle the piece to be forged. The height of the forge varies according to that of the person who has to use it. Usually the workpiece support is at waist height.
Step 10. If you want you can raise the outer wall with normal bricks to improve the smoke and heat draft, obtaining more bearable temperatures in front of the forge
It is not strictly necessary.
Step 11. Let the oven dry
The time required varies according to the climate, but on average it is about 28 days. If you can't wait to start using it, you can light a small fire in the middle to speed up the process and temper the oven before using it at full capacity.
Advice
- If you are building a chimney to drain smoke and heat from the furnace, make sure it is high enough to get a good draft, otherwise build a suction circuit.
- Using a larger gauge steel for the bottom of the oven will get better results, as it will be more resistant to high temperatures and will not rust over time.
- The brick support above the fire can be used to support the pliers and the piece to be forged, but do not use it as an anvil to strike the iron.
- Gas (propane or otherwise) is more practical than other fuels, but it's best to buy a small industrially produced forge if you intend to use gas.
- Look for other guides if you don't know how to do the masonry work.
- You should use refractory materials to build the kiln and adjacent structures, but if you don't want to do all this work you can just make a concrete base and build the kiln with square stones.
Warnings
- Be careful when working with concrete. Always wear protective gloves, boots and eyewear.
- Lighting the forge before it has completely dried can cause the mortar between the bricks to swell and crack.
