This is the time of year that I have the most time to devote to casting bullets. Like many of us I suspect, I do my casting in the garage and provide ventilation by opening one or more doors. Last week I cast 400 bullets when the temperature was 6 degrees F in the garage. Yesterday I made another 400 while the temperature was 19 degrees. We have a heat wave moving in today and I think the temperature should get over 20 degrees in the garage. I will probably cast another 400.
Yesterday the temperature of the mold kept migrating any time something interrupted my pace even slightly. I found that I had to control my ladel perfectly to direct the alloy in the exact center of the sprue hole and then continue the pore for 2-3 seconds after the cavity was full. The second cavity I then pressure fed by placing the ladel spout into the sprue hole as I pored. The alloy had to be kept about 100 degees hotter than it needs to be when casting in shirt sleeve weather.
I ended up with 5%-10% rejects which is quite high for the mold design I am using. I assume other northern types have similar problems. Not everyone can have heated garages and vent hoods. Are the tricks of the trade which can make cold casting a little easier or quicker?