cooling box isolation?

[kaidepuu]

I want to install a compressor to refrigerate the original pentry cooling box. Is there some isolation originally or must I rebuild it?

[Bob McGovern]

Our Ballad's ice box was quite large -- over 2cuft (57 liters) -- but had almost no insulation (2mm Ensolite foam on outside) and a drain in the bottom, letting the cold escape. That is fine for a daysail, or maybe overnight in a cold climate. I rebuilt it using a combination of polystyrene foam board on the inside and foil-faced polyiso on the outside. The drain went away; we will remove meltwater with a hand pump. Interior volume is now only about 1cuft (28l), but that is still enuf for a big block of ice and all the food we want to keep chilled.
icebox by Robert Mcgovern, on Flickr

Edit: I put scrap Formica (High Pressure Laminate) on the outside facing the engine compartment, because polyiso foam will burn if exposed to a flame source.