SS passivation a myth?

[specialkayme]

. . . Or John Palmer

But whatever. Put your faith in what you read on a forum about what NASA does if that's what moves you. Or Google "times NASA was wrong."

Last I checked, your kettle wasn't sending anyone into orbit.

 

[Die_Beerery]

. . . Or John Palmer

You can continue to list off any folks you like, I can promise you unless its ASTM or NASA, I will not be agreeing.

 

[Yooper]

. . . Or John Palmer

Pshaw. Some random metallurgist from some little engineering school for geeks in the UP of Michigan, who is an honorary Yooper because of living in the UP for those years..........like Palmer knows about stainless passivation just because he's a chemical metallurgist. What could he possible know about such things???????????

 

[Die_Beerery]

Pshaw. Some random metallurgist from some little engineering school for geeks in the UP of Michigan, who is an honorary Yooper because of living in the UP for those years..........like Palmer knows about stainless passivation just because he's a chemical metallurgist. What could he possible know about such things???????????

How many folks has he sent to the moon again?

 

[specialkayme]

How many folks has he sent to the moon again?

How many have you?

 

[Die_Beerery]

How many have you?

I'm not sure why you are fighting with me. I am just listing facts.

I urge you to read the link I posted about the literal standards.

OH! and

 

[Bilsch]

Stellar Solutions, a company that makes industrial passivation chemicals, has this to say about oxalic acid and passivation. Interestingly enough the article focuses on brewery applications.

"A common misconception in the brewing industry is that passivation can be done with any acid. Many brewers have an oxalic acid, phosphoric acid, and/or abrasive based cleaner handy and think that it can be also used to passivate their stainless steel. While these cleaners do help bring the stainless steel surface down to bare metal, they do not selectively remove iron, and so the metal surface created will still have a very high percentage of iron. The chromium on the surface will passivate into chromium oxide, but without a correct acid treatment, that chromium only covers at most 20% of the surface. Passivation standards like ASTM A967 do not recognize these acids for the purpose of passivating stainless steel."

http://citrisurf.com/brewery-winery-distillery-passivation/

 

[Jayjay1976]

hsa rears its ugly head once more.

 

[Bilsch]

hsa rears its ugly head once more.

It's like the plague.. you never know where it will pop up and it will kill you.
Ok, I made that last part up.

 

[specialkayme]

It's like the plague..

Too soon man.

 

[Yooper]

How many folks has he sent to the moon again?

I don't know- I'll have to ask him when I see him.

 

[Yooper]

But I use Acid # 5. Once in a while, but not very often actually.

 

[eric19312]

What is cheapest way to do a citric acid rinse at proper concentration? I bought a pound of the stuff made as a wine additive but seems like might need to use it all in a couple gallons...

 

[day_trippr]

4 to 8% by weight is plenty...

Cheers!

 

[eric19312]

4 to 8% by weight is plenty...

Cheers!

so 1/3 pound per gallon Is 4% by weight. Is there a cheaper source that the wine additive?

 

[bracconiere]

does my coating of old beer residue that won't scrub off count as passivization?

 

[Gruel]

I use lemon juice, since it already has the right concentration. Unless you want to pump gallons of it through your system, you just need a little to wet the stainless surfaces that you want to remove the iron from, so lemon juice (or lime juice) seems most convenient.

As already mentioned, the mystery of passivation then happens all by itself, as long as you and your stainless parts are in an oxygen-carrying atmosphere.

 

[bracconiere]

I use lemon juice, since it already has the right concentration. Unless you want to pump gallons of it through your system, you just need a little to wet the stainless surfaces that you want to remove the iron from, so lemon juice (or lime juice) seems most convenient.

As already mentioned, the mystery of passivation then happens all by itself, as long as you and your stainless parts are in an oxygen-carrying atmosphere.

i just picked up 5lb's citric acid off ebay for $20....lemon juice seems like it'd be expensive....

 

[Gruel]

If you need gallons, absolutely.

 

[RPh_Guy]

I use lemon juice, since it already has the right concentration. Unless you want to pump gallons of it through your system, you just need a little to wet the stainless surfaces that you want to remove the iron from, so lemon juice (or lime juice) seems most convenient.

As already mentioned, the mystery of passivation then happens all by itself, as long as you and your stainless parts are in an oxygen-carrying atmosphere.

1. Passivation does not occur at room temperature.
2. Air does not selectively remove iron from the surface of metal (i.e. passivation does not occur spontaneously).
3. Lemon juice contains a lot of other substances that may interfere with the process.

 

[Bilsch]

If you need gallons, absolutely.

So you have like a 1 quart boil kettle?

I have 3 ten gallon kettles in my system.. how many lemons is that anyway?

 

[day_trippr]

fwiw, what I read about actual acid treatment process recommended rinsing with distilled water, presumably to avoid contamination of the freshly iron-depleted surface and leaving residues. I used my RO which is pretty close...

Cheers!

 

[bracconiere]

so this is the opposite of aluminum pots? acid removes their oxide layer right? (just in case any one with a turkey fry rig is reading)

 

[NewJersey]

These arguments are the BEST
My ss brew kettle has no rust. No surface rust. No discoloration.
Why would anyone ever worry about this issue in the same circumstances???
None of my SS accessories have even a dot of surface rust.
It is now time for popcorn gifs imo

 

[bracconiere]

These arguments are the BEST
My ss brew kettle has no rust. No surface rust. No discoloration.
Why would anyone ever worry about this issue in the same circumstances???
None of my SS accessories have even a dot of surface rust.
It is now time for popcorn gifs imo

mine either....this is the first i've heard about this too......(and i've been using my SS kettle for 15 years....)

 

[NewJersey]

Ive been sideline reading arguments between plenty of intelligent people on this issue
I'd like to know the "right" answer just to answer my own curiosity.
Practically speaking? None of my SS stuff has ANY rust on it.

 

[bracconiere]

Practically speaking? None of my SS stuff has ANY rust on it.

if they do LoDo, even a microgram of iron, if it does contribute to oxygenation, would be like the pot giving them a wedgie.....

 

[Bilsch]

Ive been sideline reading arguments between plenty of intelligent people on this issue
I'd like to know the "right" answer just to answer my own curiosity.
Practically speaking? None of my SS stuff has ANY rust on it.

The right answer, as usual, is... it depends. If your gear isn't rusting and you aren't worried about surface iron catalyzing oxidative fenton rections in you beer.. then carry on the way you've been doing!

 

[day_trippr]

ahahahahaha!

 

[RPh_Guy]

Also FYI: Iron is required for tetrahydropyridine production. So if any of you make sour beers, then passivation will help avoid that off flavor.