Walk in cooler kiln

[mroldstyle]

I have a nephew that works for a convenience store chain as a carpenter, and there replacing numerous walk-in coolers. He is able to get me a couple,
 they are 9ft x 10ft each, but consist of 3 foot panels that cam lock together so I can combine the two into a 9x12,15 or 18 foot chamber. Panels are 26 g. galvanized steel with 4 inches of foam sandwiched between. The floors are stainless steel. I know the galvanized steel won't hold up, but was thinking I could spray foam the interior (have a friend that owns an insulation business) do you guys think that would protect the steel enough? Should I plan on covering the foam with plywood? Intend to purchase an l-53 kiln unit
Thoughts?? 
Thanks

[Southside]

I have three walk in coolers for the farm side of the business, including one just like you are looking at.  The foam is absolutely not water proof and will soak up all the moisture the kiln is putting into the air, as those seams are not as tight as you might imagine, especially after they have been taken apart a couple of times.  I also doubt the temperature rating on that foam is high enough for a kiln.  

Now if you were to build an air tight and water sealed insulated box within that cooler, then it would have value in adding insulation value to the elements, I guess the question is financially does that work in the end? 

[mroldstyle]

My insulation guy says 2 inches closed foam is considered a vapor barrier, and he is checking on the temp rating of it. High temp of 150 for 24 hours for sterilization, is that sound right?

[Southside]

I run at 160F, check with Stan at Nyle, @K-Guy kiln air is very corrosive due to the volatile compounds that get pulled from the wood and you want to make sure the envelope you build is protected from that.  

[K-Guy]

In the past that has not been enough and the spray foam did take on water. The new products may be better but do you want to chance it? If you are wrong it would be a costly mistake.

Note: We do not use spray on our kilns at all after trying it and having problems.

[mroldstyle]

So how are your chambers insulated?