On Tue, 13 Dec 2005 23:17:01 -0500, "Ed Huntress"
wrote:

SNIP
They do catch on fire if you get a little loose with your
shop hygiene. They also catch on fire sometimes, anyway. And don't put one
in a basement shop. Your whole house will stink of hydrocarbon fumes.

Not sure what you mean by "shop hygiene", but poorly filtered dirty
EDM fluid does seem more prone, but maybe that's because the currents
are higher?

Commercial EDM oils don't instantly "catch fire", but rather start
with little puffs of wispy flames of hot vapours bubbling up in a
flooded tank operation, or surface flames-ups for a few seconds in
surface flooding burns. Left long enough, there will be a fire, but
not instantly. That's why most EDM's have a "flame sensor" in the
safety circuit, providing some bozo hasn't jumped it out or turned it
to face away from the work area.

Kerosene is a greater real hazard, and it "stinks".

Water as a dielectric won't catch fire, but doesn't carry heat and
swarf as well either.

Take care.

Brian Lawson,
Bothwell, Ontario.