Sheet Metal Identification
I purchased some small sheets of metal at the local Restore couple years ago, always assumed it was stainless steel. It is not magnetic, which I don't believe SS or aluminum is. So, I started to polish with metal polish and rag turned black. Don't think SS tarnishes does it? Considering using it to fill in gap by water heater( new one is much smaller now), but want to make absolutely certain it isn't stainless. Anybody know a secret to testing to make sure? Thanks all!