I was given this hospital food warmer. There are however no tags identifying it but a Hobart label- no serial numbers etc... I put a 3" stack on the top and I plan on using a double hot plate warmer. The warmer still works and has reached 200 deg so I was told. My question is this: I have 6 racks that were in it but they looks like they are galvanized. I tried to scrub one rack and it doesn't change the patina of the grates. would Hobart use galvanized grates for a food warmer?? I want to make jerky but I'm afraid of using these grates. Ive called several local junk yards and nobody has used oven racks. Its been frustrating. I'd like to keep the warmer capabilities. Any ideas on this project would be greatly appreciated!