I just finished bricking my arch last week. I waited for a day that was above freezing to do it and when done I put a 250 watt heat lamp and a 100 watt light bulb in the arch , covered it up with sheet metal and some old blankets and left it for several days. I don't have my stack in place yet either. The refractory cement seemed to dry very well even though the nights were 10 to 15 degrees and the days 25 to 35.I will fire it with a small fire when I have everything ready.

george