How to Get Copper Out of a Transformer

A transformer is two or more coils of wire wound around a core of thin steel plates. In most transformers the coils are copper, though some use aluminium. The copper is easy to see once the casing is off, but a couple of kinds of transformer are genuinely dangerous to open.

Leave these alone

• Microwave ovens. The transformer sits next to a high-voltage capacitor that can hold a lethal charge after the microwave is unplugged, and people have been killed working on them. Do not open a microwave unless you know how to discharge that capacitor safely.
• Oil-filled transformers, such as power distribution transformers. The oil is a hazard in its own right, and in old units it can contain PCBs. These are a job for a licensed contractor.

Where the copper is

In small transformers, from power supplies, chargers, welders and old electronics, the coils sit in the middle of the steel core. They are enamelled wire: where you scratch the enamel, copper shows reddish and aluminium shows silver.

Getting the coils out

1. 01Make sure it is disconnected. If it came out of a microwave, read the warning above first.
2. 02Take off any casing and mounting brackets.
3. 03The core is a stack of thin steel plates, usually welded or riveted along the sides. Cut the coils flush with the core on each side, using a hacksaw or a cold chisel.
4. 04Drive the cut sections of coil out of the core.
5. 05Wear eye protection and gloves.

Is it worth it?

The copper in a small transformer does not weigh much, and the work is slow. Enamelled wire is not bright copper either, because of its coating. If you have a quantity of transformers, or large ones, send us a photo first and we will tell you how we can take them.