I am thinking of 3/4" expanded metal, probably flat maybe 1/8 or 3/16 thick so that would be maybe 8 to 10 ga I think. The racks will only be 18x26 and supported on the long sides. How do you prep them before use? Just scrub with hot soapy water I assume to start, but do you do anything special after that? They will be in an electric smoker. thank you.