Steel melter for forty bucks? Needs a KW dc supply. Also $1 100nS 30KV! Also ALSO!

I would guess that the space between the lock parts is much larger than the graphite particles and that the graphite rolls on top. It might polish the moving parts, which would be a good thing.

I was using a 12 volt 6 or 7 amp linear power supply. It's way too small for the job and was going into current foldback mode. Got sidetracked with other junk as usual. Will try a 24 volt 12 amp power supply next to get a feel for how fast that copper tube overheats.

It does heat up way more with no load than with a load.