Induction Forge Operation

General Information

This page covers the detailed setup, operation, and shutdown procedures for the Coal Iron Works 15 kW Induction Forge. For an overview of all forges, see Gas and Induction Forge.

The induction forge uses electromagnetic fields to heat metal rapidly and is ideal for forging, heat treating, and localized heating.

The induction forge heats metal much faster than a gas forge and is the recommended tool for most projects. It has a faster setup and cooldown, and is safer for many operations since there is no open flame.

For a complete introduction to the machine, watch the video below:

Safety

Always wear appropriate PPE: heat‑resistant gloves, safety glasses, closed‑toe leather shoes, and natural fiber clothing. Synthetic fabrics can melt.
The coil and workpiece become extremely hot within seconds. Use insulated tongs and keep hands clear.
Do not wear or carry any metal objects near the coil while the machine is powered. This includes watches, rings, tools, and metal fillings in clothing.
Never touch the coil or the workpiece during heating.
Ensure the water‑cooling system is running before starting the forge. Running the machine dry will cause immediate damage.
Keep the work area clear of flammable materials.
Do not operate the machine if the power cord or water lines are damaged.

Setup

The induction forge is located on a rolling cart in the Metal Shop. The following components are part of the system:

Power supply unit
Control panel with power adjustment knob and start/stop buttons
Induction coil (interchangeable)
Water‑cooling system (chiller or tap water connection)
Foot switch (optional)

Water Cooling

The induction forge must be connected to a water‑cooling system before operation. The cooling system circulates distilled water through the coil and internal components.

Check that the water‑cooling reservoir has adequate distilled water.
Ensure the water pump is running and water is circulating before turning on the forge.
The machine cannot be run without active water cooling – this will cause immediate and permanent damage.

Coil Selection

The appropriate coil must be installed for the workpiece you plan to heat. Coils are interchangeable and designed to fit specific workpiece sizes and shapes.

Select a coil that allows the workpiece to fit inside without touching the copper tubing.
The workpiece should be centered within the coil for even heating.
If you need to change coils, ensure the machine is powered off and the water flow has stopped.

Startup Procedure

Follow these steps in exact order. The water cooling must be running before power is applied.

Pre‑Start Check

Verify the water‑cooling system has adequate distilled water and is circulating properly.
Ensure the correct coil is installed for your workpiece.
Place the workpiece within the coil, centered and not touching the copper tubing.
Clear the area around the coil of any metal objects, tools, or flammable materials.

Power On

Turn on the water‑cooling system (if separate from the main unit).
Turn on the main power switch on the side of the induction forge. The control panel should light up.
Set the power adjustment knob to its minimum (fully counterclockwise).
Press the start button (green) on the control panel. The machine will begin operating at low power.
Gradually increase the power by turning the knob clockwise. The workpiece will begin to heat.
For precise control, you may use the optional foot switch instead of the panel start button.

If using the foot switch, plug it into the designated jack on the rear panel. Pressing the foot switch starts heating; releasing it stops heating.

Operation

Heating the Workpiece

The 15 kW induction forge can bring small pieces to forging temperature (bright orange to yellow) in 5–20 seconds.
Larger pieces may take 60–90 seconds to reach temperature.
Monitor the workpiece color to gauge temperature. A dark cherry red is approximately 1,300 °F (700 °C), while bright yellow is approximately 2,200 °F (1,200 °C).
Do not overheat the workpiece. If it becomes white hot or begins to spark excessively, reduce power immediately.
Move the workpiece in and out of the coil to achieve even heating. Induction heats the metal closest to the coil most intensely.

Tips for Best Results

For even heating, rotate the workpiece periodically or move it slightly within the coil.
When heating a piece that extends beyond the coil, the section inside the coil will heat fastest. The heat will gradually soak into the rest of the piece.
If the machine trips an over‑current error, reduce the power setting or heat the workpiece gradually by holding only the tip in the coil, letting it reach temperature, and then advancing the piece incrementally.

Shutdown (Cooldown)

Follow these steps to shut down the forge safely.

Turn the power adjustment knob to minimum (fully counterclockwise).
Press the stop button (red) on the control panel.
Turn off the main power switch on the side of the machine.
Let the water‑cooling system run for at least 5 minutes after turning off the power to cool the coil and internal components.
Only after the cooling period, turn off the water‑cooling system.

Never turn off the water cooling before the machine has cooled down. Internal components can be damaged by residual heat.

Maintenance

After Each Use

Allow the machine to cool with water circulating for 5 minutes before shutting off.
Inspect the coil for damage or debris. Clean with a soft brush if necessary.
Wipe down the exterior of the machine and cart.
Check the water level in the cooling reservoir. Top up with distilled water if needed.

Weekly

Inspect all water connections for leaks. Tighten compression fittings if necessary.
Check the power cord for damage.
Examine the foot switch (if used) for proper operation.

Annually

Have the machine inspected by a qualified technician.
Replace the water cooling fluid (distilled water) and clean the reservoir.

Troubleshooting

Forge does not start

Ensure the water‑cooling system is running.
Check that the main power switch is on.
Verify the foot switch is plugged in (if using) or press the panel start button.
Check that the emergency stop (if equipped) is not engaged.
Ensure another high‑draw device in the shop is not sharing the same circuit.

Forge trips over‑current error

The workpiece may be too large or too close to the coil. Use a larger coil or reduce power.
Heat the workpiece gradually – hold only the tip in the coil at first, then advance as it heats.
The internal resistance of the workpiece may be too low. Try a different workpiece or reduce power.

Workpiece does not heat quickly

Verify the coil is the correct size for the workpiece. A coil that is too large will not couple efficiently.
Check that the workpiece is centered within the coil.
Increase the power gradually.
Ensure the water‑cooling system is functioning properly.

Unusual noises or smells

STOP IMMEDIATELY and turn off the machine.
Check for water leaks or electrical arcing.
Do not restart until the issue is identified and resolved. Contact Makerspace leadership.

Machine will not turn off

Use the emergency stop if equipped.
If the panel buttons are unresponsive, turn off the main power switch.
Unplug the machine from the wall outlet as a last resort.