Red hot nickel ball in water.
https://www.youtube.com/watch?v=9qSEfcIfYbw
Previously:
https://www.homemadetools.net/forum/...992#post179790
https://www.homemadetools.net/forum/...089#post141193
https://www.homemadetools.net/forum/...2504#post96473
https://www.homemadetools.net/forum/...213#post121319
https://www.homemadetools.net/forum/...158#post100892
