J E,
Thanks might try that, I used to harden bore "spuds" in water, to keep them from warping I held them in a drill press chuck (useing water hardening drill rod). I would turn drill press on, set a can of water underneath then heat to bright red then while still running use the drill press quill to dunk the "spud" into the can of water. Can't remember every having one to warp.
Note bore "spuds" were inserted in the bore and then a dial indicator was used to center the bore in the lathe.
Dennis