Hello, While I do not know much about building an incubator, i thought maybe someone could use this info. I used to have a little giant incubator. it was made of cheap styrofoam. I used to work at Petsmart, i would always snag the boxes that the fish came in. I usually spray them out with a bleach solution but hey free is free. Petsmart gets their fish in coolers. they are pretty solid. the ones that the comets come in are square and pretty thick. the ones the regular fish come in are rectangle and still pretty thick. The lids interlock for a good tight fit. If you ask your local petsmart what day their fish come in they will usually save a couple of the coolers for you, otherwise they just end up in the garbage. Anyway thought someone who is handy might find a good use for them. i currently use them to take my eggs to market. I included a couple pics.