Rust in kettle

[dannythemanny]

Hi all,

I have a stainless steel kettle and had always cleaned after brewday using ChemClean. However, I recently bought a new SS fermenter and heard about passivating. I ordered some Bar Keeper's Friend. The stuff is amazing at cleaning, so I used it to clean the inside of my kettle as well. I rinsed thoroughly and the kettle looked new and shiny after I dried it with a towel. This was a week ago. Today, I filled it with water, ready to brew again, and noticed some rust around the volume indicators that a re stamped onto the kettle. This has never happened before - did I do something wrong with thr BKF? I had heard it was supposed to prevent rust, but to the contrary, it appears to have caused it! Any advice much appreciated.

Dan

 

[peebee]

Bar Keeper's Friend relies mainly on oxalic acid (same as in rhubarb and strawberries … and poisonous!) which actually isn't good at stripping SS back in preparation for "passivating" - which happens anyway in the presence of oxygen (including oxygen dissolved in water). The BKF is probably good at stripping back and leaving the iron exposed to oxidise (rust). Passivation attempts to create a protective layer of chromium oxide. Aggressive cleaning (wirewool is the worst) will make it worse still. Bad SS (such as cheap Chinese stuff) just isn't "stainless" and will contain large pure iron inclusions and insufficient chromium: It will rust!

Sometimes you just have to put up with regular rust removal (BKF?) or hope it sorts itself out. Another source: I once had bad rusting around a hole that turned out to be a less than SS fixing nut. Contact with rust can "infect" the SS.

 

[KGB]

ss brewtech recommend not using bar keeper's friend on etched markings (because it will cause them to fade). could that be in play?

https://ssbrewtech.zendesk.com/hc/en-us/articles/202957895-Removing-Stains-and-Cleaning-