Question: Can you overlap the wire in an inductor?
Answer: Yes. An inductor is typically made with enamel coated wire. We call this magnet wire. The enamel coating acts as an insulator. The plastic insulation on most wires is much thicker than the enamel. Remember that the more turns you have in the wire, the bigger the inductance. By using the thin enamel coating, you can get many more turns in the same volume than the plastic insulation would allow. The enamel coating isn’t as durable as the plastic, but to create a short, you need a scratch on two neighboring turns of wire. If you put too much current through the magnet wire, the wire will heat up. Too much heat, and the insulation will burn off. When you burn off the insulation, you create many shorts. These shorts bypass the loops, creating short cuts :-). And without the loops you don’t have the inductance anymore.