I purchased stainless steel exhaust pipes but not even a year later I'm starting to get rust build up. Most of it is on the hangers and welds. I'm guessing maybe these things aren't stainless but I'm also getting orange build up on the pipe. IS this normal? I thought stainless was supposed to be rust proof. I can take pics if anybody wants to host them for me, or I can just email. Any comments would be appreciated.