Every winter I hear several customers say they can't cast or size until the weather warms, because their work area is unheated. Yet, with 30 years in this business I know that the majority of bullet casters try to do all their casting during cold weather!
The simplest fix for cold weather casting, which most casters do in a well vented garage or outdoors, under a porch, or carport, etc, is an electric RADIENT heater. I’ve used one called a ‘heat dish’ which I bought from Costco for about $80. It will keep one warm as toast in temps down to at least 0 deg F if one keeps the breeze or wind from blowing on them. There are many other brands and types, but be sure to get one that spreads it’s heat over a wide area, with adjustable temperature control, and NO FAN. If the heat is fanned it becomes unafforadable fast. But with just radient, operation for the few hours most casters need it costs very little. Maybe $1 to run it for 8 to 12 hours.
As I stated above, IF one keeps the wind off himself. A simple way to stop the wind and catch some of the lost radiant heat is to hang a silver faced plastic tarp from garage or porch trusses/rafters. Be sure to choose one large enough to hang all the way to the floor, and close in a small area to work in. You’ll want the radiant heater at least 6 feet from you, and possibly up to 10 feet, so it doesn’t overheat you on one side. Most of these heaters have a heat setting knob or thermostat, and the most efficient way to use them is with the heat setting low as will give comfort, with heater set fairly close. Hang your tarp so it comes close to your back and side farthest from the heater, so air circulation on the unheated side is minimized. Keep the top open so there is plenty of ventilation to carry casting fumes away.
Another source if very inexpensive heat is infrared heat lamps. I have worked in temps as low as –20 F with just one hanging just far enough from my back to prevent scorching my heavy clothes. But I was dressed VERY warm, and even then could not stand more than about 2 hours at a time before getting inside and warming up well. Tarps to stop the breeze and two or three lamps would have made life quite comfortable, had I had sense enough to do it. Or, better yet, a radiant heater as described above. I was milling mold blocks back then, in a four horse trailer, before I got a big shop up which would hold the large planer mill. The blocks were of coarse, as cold as the air, and painful to handle. Had I been a bit more experienced in cold weather work, I would have laid the blanks in an electric fry pan set at a temperature which was low enough to prevent burning my hands. That would have stopped the awful aching of hands and arms from the bone chilling metal. This is a good trick for those who need to size an lubricate bullets in an unheated area. Temperature for your bullets should not be as high though, but just real warm to the hands. The heated bullets will do more for lube flow than heating the lubrisizer, and keep your hands from getting cold, which goes a long way from keeping the nose from running!
Another simple fix which works without a heater, for an area that isn’t extremely cold, say down to freezing or so, is to hang an old sleeping bag or thick blanket from the ceiling so it is pulled up against the shoulders and slightly around you while standing at the lead pot.
The above will allow many to use those nasty winter days casting instead of setting in front of the boob tube! Then spend those decent days which people are now spending on casting, out shooting or doing other outdoor things.