I’ve read in a few threads about passivation of stainless steel. What is this process and why is it necessary? The reason I’m asking is that I have a 20 gallon stainless kettle from 1948 , the ones that hung in the kitchens back when they made real school lunches. Anyways, my pot has a few pits in it and since it’s my boil pot , I’m not worried about infection. Would I need to passivate or not? Thanks