B31 Kill box and Tackle Station

[Yannis]

Rick,

That's what I used, XPS foam, extruded polystyrene.
However, I was told that had I used expanding foam (not XPS), the insulation would have been better, but then you run into other problems like bulging sides etc.
I was also told that there is a foam product that does not expand, you spray it and it keeps the volume that you pour in...but I'm not sure what this product is, I haven't seen it used by anyone.