I took an empty 5 gallon hydraulic fluid can and cut off the bottom to about 6-7 inches tall. I then mounted a light bulb base onto a piece of plywood and another couple on top of that to raise up the can and to make a recess for the can so it would stay put. Plugged a thermostat plug (on at 35*, off at 45*) into the base wires, put a 25-100 watt (depending on how cold it gets) into the socket. Place the can bottom over the whole thing and top with your favorite waterer. I posted some photos a few weeks ago, they should still be available via my profile link. Otherwise I can send some to you. I am currently using a 25 watt bulb and it seems to be working fine. Not too hot, not much electricity draw, just enough to keep the water from freezing.How did you make yours?
I put mine in service yesterday.... working great.
I used the cookie tins and installed a 100 watt lamp in them. I set the tins on a stone block, then set the 3 gal. waters on the heater. Wife checked them as soon as daylight came...cool water, but nothing frozen!
Joe
When we get another emply can at work I will make one more.