After building a new "Homemade" incubator, im now looking into a heat sink. I have seen many people use bottles of water and various other things, but im wondering about steel as a heat sink. I have a piece of .5 thick steel 20"x20" that would fit nicely in my incubator. From my understanding of thermal conductivity, steel would be ok. Other than being in direct sunlight most materials heat/cool-off to match the surrounding air temps. My question is...would the steel plate work if placed on the bottom of incubator, with the egg turner sitting directly on the steel?. I dont think the steel would at any time give off a higher temp than the surrounding air?. Just figured with it being 1/2 thick and 20"x20" it would have a great mass for storing heat. thanks for any help.