Off grid fridge sweating lid fix

[dnix71]

I bought a 40 quart Engel 12v fridge many years ago and it works well to this day, except that the top of the lid sweats in warm weather.
This results in a pool of water on the top. A "fix" for that was to lay several bath towels on the lid for better insulation. They wick away the water and it evaporates. But after a while the bottom towels become moldy.
Since I have off work this week and have been doing a different repair project each day, I figured today I would refoam the top shell of the Engel.
Using a small straight tip screwdriver I was able to separate the top and bottom shell halves and remove the original foam in more or less one piece. There is no visible flaw in the foam, it just doesn't seem to do it in the warm humid south Florida summer.
I had 3 cans of Dow Chemical 16 ounce "Great Stuff" 'green version' low expanding foam sealer, so that's what I used. The original foam seems to be Dow's industrial cousin of the same. It took about 1 1/2 cans to fill. The foil safety label under the lid doubled as the expansion port for foaming the lid. I simply peeled it back and replaced it when the job was done.
The dark piece of material stuck to the foam in the third picture is a flat piece of metal that reinforces the lid cable screw. The lid will open only 90 degrees with the cable attached. There was a small amount of surface rust on some parts, but overall the metal pieces are in good shape considering how much humidity they are subjected too.

[OperaHouse]

Good fix.  Anyone with a hot tub has experienced going from being able to lift the cover with a finger to it being a back breaking experience.  Most foams absorb water vapor.  I had an upright freezer that rusted a hole through the back wall.  I used a foam patch over it till we used up the food and got rid of it. 

[dnix71]

The original foam didn't feel heavy or wet. I don't think it got water logged. But there is no vapor barrier in there. After I did the job it occurred to me that a layer of mylar or foil would have added some insulation and moisture resistance. If I was to do it again, I would look for some building grade vapor barrier foil to line the bottom half of the shell.

When I was in college, we repanelled the dorm rec room and forgot the vapor barrier. Two days later we had to rip off all the warped panelling and add plastic sheet to the block wall and panel it again.