A few passivation questions

[Razorback_Jack]

Hello all. I’ve got a few questions about passivation, since this is the first time I’m actually passivating with citric acid. I’ve used a high concentration of StarSan in the past, but I realize that the current research disproves its passivating qualities. So, going with citric acid.

1. It’s been a while since I washed my newest fermenter with TSP, but I did not get around to passivating it yet. Since it’s been a few months, can I just kinda wipe inside with a damp paper towel before passivating? Or if there’s no foreign matter in there, should I just go citric on it?
2. It’s a Chronical 2.0, and bulkheads are welded outside with ferrules. I’ve always wondered, should ferrule grooves be passivated as well? Of course a little wort gets in there, even with the gaskets, but could that moisture over time promote rust on those grooves? Maybe soak a cloth in citric acid, and rubber band it around the bulkhead, then rinse off with a hose? Or, am I overthinking?
EDIT: I just remembered I have some Citrisurf 77 Plus spray. This could work for the outside ferrules, if necessary.
3. After draining the citric acid, is it okay to flush down a toilet, or how should it properly be disposed of?
4. Going to rinse after passivating, with distilled water. Does that rinse water need to be hot as the citric solution was, or can it be rinsed with just cool water? Probably going to use the CIP for this rinse.

Cheers!

 

[Indian_villager]

You are ok to just grip it and rip it with the citric acid. As for rinsing, you can get away with just rinsing with distilled water, but if you want to be really safe I'd suggest hitting it with tapwater + baking soda to neutralize and then hit it with the distilled water. As for the ferrules you can use the citric spray or just wipe it down with bar keepers friend.