On Mon, 01 Sep 2014 06:46:31 -0500, Karl Townsend
wrote:

spent the day yesterday helping the kid get his new shop up and
running...

Ain't no way he'll have it it tight enough to heat 24X7 for a MN
winter this year. many years ago, I took old car radiator coolant to
use in my old shop - just added oil. Well, 30 years later I guess this
is bad form. Will RV antifreeze plus oil work OK in his CNC mill?
Other suggestions?

Karl
Greetings Karl,
I don't know how anti freeze will affect the coolant but I wouldn't be
surprised if had a negative effect. What about putting some mixed
coolant in the freezer to see what temp it freezes at? And what about
putting a submersible heater in the coolant tank? That might be better
anyway because really cold coolant on hot cutting tools might shorten
the life of the tool. How much would it cost to keep the coolant at 40
or 50 degrees? I know it gets cold where his shop is and I don't have
much experience with weather that cold for that long.
Eric