Turboroadser, thanks for the welcome! How about screwing down the sheet metal shielding to the locker, and then fasten the insulation to sheet metal with smaller screws.. That way the screws don't stick out of the locker (except the few sheet metal mounting screws). Also, that would eliminate any compression of the insulation.
jrow, its a metal locker. I need something tall and skinny to cure long knives, sword blades, gun bbls and full gun frames. Space inside is not a worry except it must be tall. i want insulation on the inside so i can mount a box with the PID, and SSR box on the outside surface on the oven..
I'm using a rediculous moly based coating called 'molyresin' from John Norrell. Have you heard of it? I do coating stuff at work sometimes so i have nice samples of good stuff to paint with like a rediculous caustic sand blased parts cleaner (MI-Clean 100 from Hubbard hall
http://www.hubbardhall.com/files/2002019.pdf 
), PPG Zinc Phosphate, PPG chrome free conditioner, etc..
I will provide updates as this gets built!
Any thing wrong with mounting SSR and PID to the oven?
Thanks again, twistedneck.