The oven is NOT that hard to build !!!, My brother is a designer for a tool and die company in the North, and he has made several different ovens.
The problem your gonna have is the dip tanks for the " wash" and the demagnatizing to get the powder to " stick" to the metal.
I am NOT saying that it cant be done, just that you are gonna have alot of trial and error ( spotty powder coverage).
Good luck with it
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