I had a feeling it would be beer stone, glad you were able to clean it up. Polishing up the inside of the fermenter with barkeepers friend is enough to help with the beer stone, no need to do any other steps. Just make sure you clean it up good before transferring beer into it.Good news, I used barkeepers friend and a **** ton of scrubbing with the non scratch scotch spong/scurbber part and it is beer stone. I have a couple spots I missed so I'm going to scrub it more tonight. Does anybody know how long it takes to get passivated because I need to use this tonight for a brew night. Maybe I'll just use it then give it another good scrubbing after this batch ferments.
Literally BKF my keggles last night after posting here (they had a little beer stone at the bottom and a small rust spot at one of the creases) and they look brand new again.Although SS Brew recommends "passivating" with StarSan in reality StarSan does not passivate stainless steel. The welds are polished and should be passivated from the factory. There is nothing you can do (or need to do) from home other than giving it a good clean with either dish soap (I like this as it cuts any machining oils) or Bar Keepers Friend.
Don't take my word for it. Listen to John Palmer (Godfather of homebrewing) who's background is metallurgy. He reiterates what I'm saying.
Side note: This is why I get so heated when misinformation is spread. Guys like YeastMode are just looking for a simple answer and they need to weed through post after post of mis-information.
I have two SS BrewTech Chronicals, one that I got over two years ago, and the second just 4 months ago, and both still look like brand new.
Stainless does pit from chlorinated cleaners, so they are correct that if that's what you are experiencing. Yet to me it looks more like poor cleaning and care practices all around. If you passivate stainless correctly, then clean using the prescribed methods you shouldn't ever have any issues.
I'm also pretty sure that if it was a problem with the material itself, this would not be an isolated incident. Think about it, they likely purchase the sheet metal in huge quantities mill-direct. Like others have said, to keep the cost down. If there was a bad lot of steel, we would likely see tons of posts everywhere about inferior material, since it would infect hundreds of units. I did a quick google search and the fact that you are the only one with a pitting issue, kind of isolates the issue to something you are doing. When I have beerstone or some other stuck on stain, I use bar keepers friend, its awesome stuff, have you given something like that a try?
I know their support is well regarded here, so if they thought you were exploiting them for a free Chronical, I could see why they put the brakes on that. I would try to give it a good polishing with Bar Keepers, and see what that does...