Doug Kanter wrote:
"Mark" wrote in message
oups.com...
if you leave the top open so the water can expand, won't that work ok?

Mark


You'd think so, but I left a watering can filled with water on my porch. It
froze solid and the ice pushed the bottom of the metal can into a round
shape. Very weird. Half the top of the can is wide open - plenty of room for
expansion.

If the ground was warmer than the air then it probably froze from the
top and sides down towards the ground, creating a nice plug that
apparently was stronger than the bottom of the can.