made of heavy plastic... they stand up to abuse.

I also freeze at least one gallon of new fresh water... the icy melt water is quite refreshing. This is what I have done for years while car camping in BAJA. So I am trying to see how many days I can get in the ixe box on the sea.

To actually build a new icebox would take a huge amount of very dirty work... not something high on my list.