Meg got this bird bath de-icer for her birthday. Last night it dropped to 20 degrees, this morning the bird bath water was slightly warm this morning. The other bird bath was frozen solid.
We had two bird bath stands where the tops broke and were not repairable. So I found this ceramic bird bath top at Southern States ( I did not buy the low end bird bath heater that Southern States sells) and it worked beautifully. The dragonfly and tiles I made this past summer in a tile making class at Claymakers in Durham. Used thin set mastic for setting in the tiles and dragonfly. When I attached the bird bath top to the bottom I used a handful of mortar mix used in setting bricks, the thin set would have worked as well.
FYI the tiles set in this bird bath would make it prone to breaking from a good freeze if filled with water with out the de-icer. If you want to use a bird bath in the winter without a de- icer you should use a bowl shaped one. This way when it freezes the ice can just lift itself out instead of breaking the bird bath.
In case your wondering this is a Farm Innovators Bird Bath De-icer model C-50 (150 watts) It comes with a 3 year warranty too. I bought it locally at Cynthia Fox's Wild Bird Center of Chapel Hill. The Wild Bird Center has been there forever and is a great place to find neat bird stuff.