If that old spool is metal it won't work, the whole spool gets magnetized.

No, magnet wire. Copper wire with some kind of shellac coating. Had to scrape the coating off to make electrical connection. Came out of a MOT (secondary high voltage winding).

I have a kitchen cabinet to build today, won't be messing with coils anytime soon - at least not today.

 

No, magnet wire. Copper wire with some kind of shellac coating.

I understand the wire, but what I was talking about is the spool itself.

 

Spool is plastic. Approximately 3/4 inch diameter, about 3 1/2 inches long with wire spooled onto that of close to 2 inches across the diameter of the spooled wire.