Hi Fleur

If you have a large box you can cover your work and put a lightbulb in the box for heat.

Thanks tufaenough -- I could put it in a warmer garage too but I need to know what the minimum temperatures ARE. Then I can deal with either stopping the casting or with moving or warming them to an acceptable temperature

From what I've heard 50 degrees is about the lower limit for what we do. You may hear about some pro's pouring projects below that but their parameters are different. Below that temperature hydration (curing) may stop and it won't start again. Our pieces are smaller and therefore don't have the mass to retain temps needed for proper curing.

So what we need are adequate moisture and enough heat to cure our pieces properly. Pieces, even under a box, if they are laying on cold ground may not retain enough heat to cure right. Pieces cured at cooler temps need longer to set up too. Give them enough time to cure before demolding. Hope this helps.