It turns at about 225rpm, that was the maximum for the 10 inch stone
and not sling all the water off. :-) It works great for metal removal on
a new square-edged knife blade-blank, makes sharpening a lot quicker with
no temper drawing of the thin edge, if I'm careful. Water or not the blade
can still get hot enough to draw the temper if you bear down on it and
grind in one spot too long.

Realizing the problem with the heat didn't seem to depend on whether the
grind stone was wet or not, tried using it dry and found out it actually
works better dry. So I've been using it dry ever since. :-)