"Mike in Mystic" wrote in message .com...
I agree with , Ed, although thanks for the suggestions Gerald.

I just can't afford to install much more for heat than what I'm using - a
simple job site (non-vented, as you surmised) propane heater. I understand
about the source of the condensation, I just didn't expect there to be such
a difference in how the different cast iron surfaces in the shop behaved in
that environment.

The propane burner requires about 10 cuft air for each 1000 btu
generated. Each 10 cuft of air burned generates about 1.6 cuft of
water vapor. That's a LOT of water.

To prevent moisture buildup in the room you must get rid of the water
generated by providing an easy exit for it; the exhaust gases from the
burner should go out a stack & not directly into the room.

Also try spraying a thin coating of a non-wetting agent like a
silicone onto the cold cast iron surfaces. That will slow down the
condensation of the water.