Removing copper wire from alternator core

When I started, I was getting a lot of alternators which I'd separate into Cast Aluminum, Irony Aluminum and #1 Copper. Getting the copper wire from the alternator armature meant getting out the cardboard that held the wire in. For quite a while, I used needle-nose pliers to grab all those pieces of cardboard and pull. Very labor-intensive and didn't always work, so I'd use a small punch (like a leather-work punch) to work it out. Even more labor-intensive to the point that it wasn't cost effective. I'd also tried using a chisel to widen the spaces so the cardboard would fall out..

I'd been told about throwing the armatures in a fire to burn the cardboard so I tried it in a bonfire. I'd done this in winter, so after they got real hot, I fished them out of the fire and threw them into the snow to cool. All I got for my efforts was charcoal that was even harder to deal with than the cardboard.

Then one night I got a BFO (Brilliant Flash of the Obvious). I'd been loading the woodstove, so I got a real good bed of coal, threw in five armatures, completely covered them with the coals, threw in a couple pieces of oak on top of that and left them for about 15 minutes. When I came back and fished them out with the poker; the armatures were cherry-red, the wire was even redder and the cardboard was completely burned away. Threw the armatures in a bucket water (listen to the LOUD hiss and watch the steam) to cool down. Now the wire practically falls out.

No. I can't sell burnt wire here, either. There is no sign of burning as there is with burning off insulation because you are not burning anything off of the wire and the wire, itself is not burnt. All your burning is the cardboard that holds the wires in.