Lots of great advice, yes the fridge lost it's freon as it quit working. It was repaired about a year ago and not getting cold. There appears to be a crack at one of the tubes inside. I'll have AC buddy check it out.
The inside looks like aluminum painted white, only plastic is the door shelfs (one piece) and the edges of the box where the door closes.
Did a search and found this:
This gives me ideas to get this built. I am open to more ideas while I build my 250 gal RF smoker.
One person mentioned foam? How easy is it to remove the aluminum side and replace the insulation? Curious to why not use foam as I have seen some built with foamboard? And if I do replace with another insulation, is fiberglass ok or does it have to be fire type insulation (expensive)?
Not sure which heat source I'll do, was thinking more of electric since propane gives off lots of moisture.