Stainless passivation - air dry wrong info? I have streaking, help please!

[Rev2010]

So Five Star Chemicals' data sheet for their acid says to air dry for passivation. They state it's necessary to achieve proper passivation. Ss Brew Tech recommends this too. However, my first Ss Brew Bucket I rinsed after passivation and it's still all nice and shiny inside but my two new one's that I let air dry have brown streaks that won't come out! I Googled "stainless passivation streaking" and found a thread on Probrewer where a poster quotes another manucfaturer I believe that says it's important to not let it air dry: http://discussions.probrewer.com/showthread.php?30355-Rust-streaks-in-tanks-following-passivation

The original poster said under magnification he can see the stainless was pitted. What's the story here? These streaks won't come out on either fermenter. Was the Ss and Five Star information wrong? Do these need to be returned for exchange or will something like re-passivating them and rinsing them fix this? *EDIT - I also emailed Ss about this.

 

[rivalry15]

That may be some of the machine oil from the factory, try more tsp and hot water and give it a good scrub. I had to wash mine out a few times to get it clean

 

[Rev2010]

That may be some of the machine oil from the factory, try more tsp and hot water and give it a good scrub.

It's definitely not factory residues. I've already done a good TSP cleaning and this is only showing on the two fermenters (of three) that I let air dry. My first one that I rinside after passivation is nice and shony all throughout the inside.

Ss responded saying some discoloration after passivation is normal and that if it bothers me Bar Keepers Friend will take it out, but of course be careful around the volume markings. What I'm doing instead is using 1 gallon of water to 1oz of StarSan and letting it sit for 20 minutes, like original passivation, then I will rinse it out and see if the streaks are still there. The streaks resemble those I get in the kettle which comes out this way, but that's caused by beerstone and beer hasn't been in these two fermenters yet. But I'm bugged enough by this to try it anyway. Was planning to use on of them for my IPA tomorrow but if these remain I may just use my plastic fermenter until I sort this out.


Rev.

 

[Stillraining]

There's times I'm just so glad Im not OCD...

 

[Rev2010]

There's times I'm just so glad Im not OCD...

Hey man, I'm just concerned that perhaps letting the acid solution air dried damaged the stainless on these brand new fermenters. I'm concerned also because I'm brewing tomorrow and planned to use one. Like I said, my first one that I didn't air dry is spotless and these streaks won't wash out. I'll know shortly after the re-passivation and rinse attempt.


Rev.

 

[Rev2010]

OK, one down so far and the acid solution appears to have removed the streaking, Phew. 15 minutes or so more to go on the other fermenter but I'm fairly certain this took out the streaking.

*EDIT - OK, both are good now after re-treating with just one gallon and rinsing afterward.


Rev.

 

[rivalry15]

Glad you got it all sorted out.

 

[k1ngl1ves]

Could have just been from water + air drying. Did you use tap?




I've got OCD, and I've got it baaaaaaaad. Lol! I wouldn't have been able to sleep tonight. I would have been in the garage remixing an acid solution at 3am. Lol!


I'm glad you figured it out. Now I'm wondering about my kettles...

 

[rivalry15]

Yea I'm the same way, always worried if it's clean enough to brew. Better safe than sorry

 

[chrisjpryor]

How are you guys soaking your stainless conicals in the acid? I'm getting a new 7 gallon conical next week and am wondering how to soak it. Filling it with acid is one thing, but how big of a container will I need to be able to soak the outside? Do I even need to do the outside?

 

[jddevinn]

How are you guys soaking your stainless conicals in the acid? I'm getting a new 7 gallon conical next week and am wondering how to soak it. Filling it with acid is one thing, but how big of a container will I need to be able to soak the outside? Do I even need to do the outside?

I didn't do the outside and used a CIP nozzle to use less solution.

 

[Rev2010]

Do I even need to do the outside?

No, not unless you are going to have it sitting in some high humidity environment. Some have said they get some rusting on the outside in their fermentation chambers and others have no issue. Probably best to reduce the humidity in one's fermentation chamber if this occurs but if it's not possible you can treat the outside.


Rev.