The frost is on the pumpkin

[rodman gilder miller]

For many years, now, as Halloween passes and the hard frosts begin, I have been worried over my glass crucibles... not the hot one filled with glass, but the retired pots decorating gardens and becoming birdbaths. Many years I have taken care to empty the water when a cold spell is upon us.

Recently, I have realized that I have never had one crack and maybe the thickness of the crucibles protect them. Have other blowers had the same experience?

Several year ago, I started insulating the surface of the water in the crucibles by floating a circle of foam wrapping (poly-ethylene?). This delays the top of the water from freezing. This is an easy solution to the potential problem, but is it needed at all?

[Eric Trulson]

I'm sure they'll crack over enough freeze-thaw cycles, just like anything, but I wouldn't worry about it too much. Most pots are an inch or so of good solid stone and don't have any undercuts, so the ice layer on top can get pushed upwards by the water below freezing & expanding, instead of putting all that stress into the pot walls.

So catastrophic failure seems unlikely. The freeze/thaw cycles will just keep expanding the existing cracks in the wall until some part of the pot wall finally gives. More likely to be next decade than next year though.

[rodman gilder miller]

Thanks, Young Turk Eric. You are probably right that the pot thickness will win out over the ice thickness.