SpanishCastleAle
Well-Known Member
FWIW, Stainless Steel also has a passive oxide layer...it's why it is 'stainless'.

EDIT: BTW, the tank we use for that hot caustic is stainless and the racks we use in it are stainless. Caustic is in there 24/7/365 and we're using the same tank and racks for the last 10 years...but the racks ARE getting a bit ugly.
Not really. It doesn't really damage the stainless although it can strip the oxide layer...but that should come back naturally. At my work we routinely put stainless in ph>12 hot caustic solution (intentionally...to clean it) for at LEAST 30 minutes...it just comes out shinier than it went in.Stainless is also damaged by high pH.
EDIT: BTW, the tank we use for that hot caustic is stainless and the racks we use in it are stainless. Caustic is in there 24/7/365 and we're using the same tank and racks for the last 10 years...but the racks ARE getting a bit ugly.