Author Topic: Passivation  (Read 1395 times)

Offline majorvices

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Re: Passivation
« Reply #15 on: July 07, 2022, 05:13:21 pm »
I guess the difference to me is "sorta reminds me of metallic" as opposed to "I'm literally licking the sides of an old chevy fender." ;)

Of course. But why not list all effects and causes?

Sure, why not? No argument there. But if you say "metallic, " the first thing that comes to mind is ferrous sulfate, not oxidation.

Offline denny

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Re: Passivation
« Reply #16 on: July 08, 2022, 08:48:55 am »
I guess the difference to me is "sorta reminds me of metallic" as opposed to "I'm literally licking the sides of an old chevy fender." ;)

Of course. But why not list all effects and causes?

Sure, why not? No argument there. But if you say "metallic, " the first thing that comes to mind is ferrous sulfate, not oxidation.

For me, it's the opposite.
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Offline majorvices

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Re: Passivation
« Reply #17 on: July 08, 2022, 09:52:06 am »
I guess the difference to me is "sorta reminds me of metallic" as opposed to "I'm literally licking the sides of an old chevy fender." ;)

Of course. But why not list all effects and causes?

Sure, why not? No argument there. But if you say "metallic, " the first thing that comes to mind is ferrous sulfate, not oxidation.

For me, it's the opposite.

Well maybe you've tasted more beers from stainless steel that needs passivated than you realize.  ;) lol

Offline denny

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Re: Passivation
« Reply #18 on: July 08, 2022, 09:58:00 am »
I guess the difference to me is "sorta reminds me of metallic" as opposed to "I'm literally licking the sides of an old chevy fender." ;)

Of course. But why not list all effects and causes?

Sure, why not? No argument there. But if you say "metallic, " the first thing that comes to mind is ferrous sulfate, not oxidation.

For me, it's the opposite.

Well maybe you've tasted more beers from stainless steel that needs passivated than you realize.  ;) lol

Maybe, but I chalk it up to the fact that homebrew equipment doesn't need passivation (usually).
Life begins at 60.....1.060, that is!

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"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

Offline majorvices

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Re: Passivation
« Reply #19 on: July 08, 2022, 08:37:09 pm »
I'm just pullin' yer leg anyway. I don't think I ever passivated homebrew equipment before either. Breweries use harsher chemicals and a lot more stainless steel real estate so they will definitely need it more.

Offline narcout

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Re: Passivation
« Reply #20 on: September 14, 2022, 03:14:04 pm »
Some information on the how and why of passivation.

https://modernbrewhouse.com/wiki/Passivation#

I tried the citric acid passivation technique outlined on the website above last night.  It was pretty easy.
Sometimes you just can't get enough - JAMC

Offline Fire Rooster

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Re: Passivation
« Reply #21 on: September 15, 2022, 03:22:20 am »
Two SS pots are cleaned with Bar Keepers Friend soft cleanser every brew day.
Use soft sink sponge, rinsed well, then wiped dry with paper towels. (Procedures on bottle)
Since Bar Keepers Friend has Citric Acid, it's Passivating to me.

https://barkeepersfriend.com/products/soft-cleanser/

Ingredients:
Water, Mineral Abrasive, Citric Acid, Oxalic Acid, Surfactant, Citrus Fragrance

Been down this road before.

https://www.homebrewersassociation.org/forum/index.php?topic=36465.msg457045;topicseen#msg457045


« Last Edit: September 15, 2022, 01:40:24 pm by Fire Rooster »

Offline MDL

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Re: Passivation
« Reply #22 on: September 17, 2022, 09:54:48 am »

Offline denny

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Re: Passivation
« Reply #23 on: September 17, 2022, 10:28:41 am »
I have not passivated any of my SS equipment. I've experienced no problems due to not passivating. What am I missing?
Life begins at 60.....1.060, that is!

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Offline BrewBama

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Passivation
« Reply #24 on: September 17, 2022, 02:23:26 pm »
I thought stainless passivates via exposure to air. . I’ve never done anything but wash my stainless components.

Offline denny

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Re: Passivation
« Reply #25 on: September 17, 2022, 02:49:11 pm »
I thought stainless passivates via exposure to air. . I’ve never done anything but wash my stainless components.

Same understanding and action here. Ill try to remember to ask Palmer whats his take on it is. He'll know if anyone will.
Life begins at 60.....1.060, that is!

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"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts." - Bertrand Russell

Offline narcout

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Re: Passivation
« Reply #26 on: September 18, 2022, 08:53:33 am »
I thought stainless passivates via exposure to air. .

The first three paragraphs from the wiki referenced above explain the difference between the two definitions of passivation that cause confusion.  The final sentence of the third paragraph is the most concise explanation:

"It's understood that stainless steel naturally 'passivates' in a chemistry sense by spontaneously forming an oxide layer. However, the definition of passivation used in this article is the process of using an acid treatment to selectively remove iron, which greatly improves the natural passive layer."

I have not passivated any of my SS equipment. I've experienced no problems due to not passivating. What am I missing?

For the people who are very focused on preventing oxidation, removing surface iron from stainless steel with an acid treatment is another brick in the wall.  Otherwise, I don't think it's something to be concerned about unless you are having issues with corrosion.
Sometimes you just can't get enough - JAMC

Offline Fire Rooster

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Re: Passivation
« Reply #27 on: September 23, 2022, 04:34:09 am »
There are many grades of SS, as the grade goes up, so does the price.
I have a cheap Walmart SS stock pot that rusts if you just look at it (not used for brewing).
The frequency of requiring passivating (or done at all) depends on grade of SS.
The lazy monster is powerful, some would rather spray and forget.

Below copied from various sources on the internet.

So what exactly is 18/10 Stainless Steel and how does this compare to 18/8 and 18/0?
18/10 stainless steel, just like inferior 18/8 and 18/0, are fractions that explain the percentages of chromium and nickel alloys added to stainless steel in order to reduce rust and enhance shine and durability. 18/0 contains limited nickel and is, therefore less resistant to oxidation. 18/10 provides the highest amount of nickel which produces the greatest resistance to rust and longest-held polish.

Some stainless steel corrode more easily. Others do not. Where stainless steel is used:

The main alloying element in stainless steel is chromium (the proportion in the alloy is 12-20 %). To improve corrosion resistance, nickel, titanium and molybdenum are also added to the alloy in varying amounts, depending on the properties required. To keep it simple, we will look at the most common stainless steel grades AISI 430, AISI 304 and AISI 316 / 316L.

Grade AISI 430 is a low-carbon chromium-iron stainless steel and contains no nickel at all. Thus, oxidative reactions can occur in a very short time with this steel grade and the application of the material is therefore rather limited.

Material AISI 304 is probably the most common grade in the stainless steel family and contains at least 17.5 % chromium and 8 % nickel. This nickel content ensures the formation of an oxide layer on the surface, which gives the steel good corrosion resistance and makes it resistant to a wide range of chemicals. These properties enable AISI 304 to be used in many areas, such as architecture and the building industry, the food industry, the construction industry, apparatus and mechanical engineering, vehicle construction, sanitary and catering products, household appliances and many more.

AISI 316 / 316L is one of the austenitic steels that is particularly resistant to corrosion thanks to the presence of nickel (at least 10 %) and molybdenum (at least 2 %). This material is therefore recommended for use in environments where there are particularly aggressive factors such as chemical stress, sea water, adverse weather conditions or similar. It is used in the architecture and construction industry for projects near the sea and air with high salt content or other locations that place higher demands on the material in terms of their quality. Grade AISI 316 / 316L is also found in large quantities in the pharmaceutical and medical industries, in tanks, silos and containers, yacht and ship construction only to name a few.

https://techiescientist.com/does-nickel-rust/

AISI
https://en.wikipedia.org/wiki/American_Iron_and_Steel_Institute

Then there's "all clad", and aluminum encapsulated in bottom of
pot to conduct heat, aluminum is a better conductor of heat.

« Last Edit: September 26, 2022, 02:02:47 am by Fire Rooster »

Offline Fire Rooster

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Re: Passivation
« Reply #28 on: September 25, 2022, 06:33:26 am »
FYI

High end brew kettles ,I've seen, are made with 18/8 SS (304).

High end cooking stock pots are made with 18/10 SS (316).
« Last Edit: September 25, 2022, 06:50:08 am by Fire Rooster »