Cindy - Glass is most prone to shock when heated too quickly through and past the strain point (~600 degrees). It's not an absolute temperature effect so much as a rate of temperature change. Depending on formulation or how well the starting rods were annealed, some glass is more sensitive to the fast rates of change experienced when introduced into a flame (ie 'shockier') than others. The only thing I've found when working during cold weather, as you're asking, is that I have to be slightly more patient (maybe 15 seconds more) when introducing a rod into the flame than when it's summer. Occaisionally, I find have to also pre-warm certain colors during the winter that I may not have to when it's summer. If you're annealing your beads as you go, then the air temperature won't matter to your finished product, either.
I think it's really more a matter of your personal comfort and how well you can shield you and your setup from the elements since you're working outdoors.
Linda
|