how to keep automatic waters from freezing in winter?

[arch_cpj]

Im going to use a electric dog bowl 19.99 at TSC Ill fill it 2 times a day ought to do fine

 

[swimmer]

Amazon and Wal Mart.com have a few different types of heated dog bowls. My question is can I put my plastic waterer on top of the heated pan mentioned earlier? One of those would be very easy to make. I'm guessing it wouldn't get too hot and melt the plastic, but I don't know. Has anyone put their plastic waterers on top of a heated base?

 

[marbekschicks]

As previously posted, I used the cookie tins with a 40 watt lightbulb in them for the past winter. I had the plastic 1 gallon waterer on one for a good 3 months. On another one I had a galvanized 2 gallon waterer then had a 5 gallon bucket waterer that was attached to a plastic oil drain pan from Walmart. We had them turned on almost continuously for 3 months. When nights were below freezing and days heated into just the 40's or low 50's we left it on. There were no signs of melting, warping or overheating. The cookie tin did not get very hot.