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Old 12-15-2013, 09:55 PM   #11
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Here is the procedure from a 3+ year old post on passivisation:
"You can repassivate with citric and ascorbic acid in hot water like we do for SS repassivation after welding or grinding and breaking the surface passivation. A 50-50 mix of 1 Lb acid blend in 4gallons of water, heated to 180 degrees, and left to cool for about 6-8 hours will extract the soluble iron and rebuild the oxides to protect the stainless steel where it has been heat affected. This is slower than the nitric acid method but safely do able by the homebrewer, and is the method of choice in the food and beverage handling industry these days. You will only need to cover the weld area, not fill entire keg as only weld or grinding/ polishing area needs attention."

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Old 12-16-2013, 01:17 AM   #12
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Quote:
Originally Posted by Bensiff View Post
There are a few spots of minor surface rust on the inside of ports. Probably due to the heat from the welds combined with that area not getting polished afterwords. If your keggles are rust free you are benefitting from the oxide layer doing its thing, even if you didn't take the steps to aid in the development of it.
I am benefiting from my knowledge and experience I have in working with stainless steel.
I never use any consumables that have been in contact with other metals other than stainless steel.

When companies manufacture products made of stainless steel it is hard to insure with 100% certainty that stainless materials have not been exposed to contaminates. Passivation is a measure to insure that stainless is free of contaminates so that it's protective oxide layer can form undisturbed.
Being that I am the only one that has worked on my equipment I can feel confident that I took the necessary precautions to prevent contamination.

It's one thing to be cautious when producing equipment worth tens of thousands of dollars. You don't want to take any chances.
But a kegle or a pot? I'm sorry, I think people worry too much.
I mean how much stainless steel cookware do people have in their homes?
Do you think anybody worries about passivating their cookware?

I'm not saying everyone is foolish for wanting to do it. I just think people worry too much about it.

Stainless steel is not a ceramic doll. It's pretty effin tough! That's why it's so popular.
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Old 12-16-2013, 01:53 AM   #13
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Quote:
Originally Posted by dmfa200 View Post
I am benefiting from my knowledge and experience I have in working with stainless steel.
I never use any consumables that have been in contact with other metals other than stainless steel.

When companies manufacture products made of stainless steel it is hard to insure with 100% certainty that stainless materials have not been exposed to contaminates. Passivation is a measure to insure that stainless is free of contaminates so that it's protective oxide layer can form undisturbed.
Being that I am the only one that has worked on my equipment I can feel confident that I took the necessary precautions to prevent contamination.

It's one thing to be cautious when producing equipment worth tens of thousands of dollars. You don't want to take any chances.
But a kegle or a pot? I'm sorry, I think people worry too much.
I mean how much stainless steel cookware do people have in their homes?
Do you think anybody worries about passivating their cookware?

I'm not saying everyone is foolish for wanting to do it. I just think people worry too much about it.

Stainless steel is not a ceramic doll. It's pretty effin tough! That's why it's so popular.
And anyway doesn't SS saelf passivate over time, taking steps to passivate it just speeds it up. And anyway if we are really worrying shouldn't we be pickling any heat affected SS before passivating anyway - not something I think the weekend DIY should try without fully understanding the hazards.
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Old 12-16-2013, 12:58 PM   #14
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Quote:
Originally Posted by dmfa200 View Post
I am benefiting from my knowledge and experience I have in working with stainless steel.
I never use any consumables that have been in contact with other metals other than stainless steel.

When companies manufacture products made of stainless steel it is hard to insure with 100% certainty that stainless materials have not been exposed to contaminates. Passivation is a measure to insure that stainless is free of contaminates so that it's protective oxide layer can form undisturbed.
Being that I am the only one that has worked on my equipment I can feel confident that I took the necessary precautions to prevent contamination.

It's one thing to be cautious when producing equipment worth tens of thousands of dollars. You don't want to take any chances.
But a kegle or a pot? I'm sorry, I think people worry too much.
I mean how much stainless steel cookware do people have in their homes?
Do you think anybody worries about passivating their cookware?

I'm not saying everyone is foolish for wanting to do it. I just think people worry too much about it.

Stainless steel is not a ceramic doll. It's pretty effin tough! That's why it's so popular.
I understand what you are saying, I haven't bothered with my other pots and equipment and never had an issue. However, when I have nearly $2k tied into custom pots and there are a few areas that have surface rust, I know they need a little more than a scrubby and PBW. So, my point isn't to debate the merits of passivation...just need to know how to do it.
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Old 12-16-2013, 02:17 PM   #15
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Some research done by Boeing shows a 15% by weight solution of citric acid used at ambient temperature with a two hour soak is as effective as nitric acid or better.

http://www.astropak.com/downloads/te...assivation.pdf

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Old 12-18-2013, 12:48 AM   #16
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If your homebrew store carries it, you can also use Five Star Acid #5 (phosphoric and nitric acid mix).

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Old 12-18-2013, 02:54 AM   #17
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These guys have some good information on using citric acid for passivating. We did an alkaline wash and then one of their citrisurf products for a new tank at a small brewery where I help out. You can passivate at lower temps but have to run the process a little longer.

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Old 12-24-2013, 05:37 PM   #18
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Hey guys, I have never passivated any of my stainless. I just got one of the stainless conical brewbuckets from ssbrewtech. I have not used it yet and think I'll try this. I don't have citric acid but I do have a new can of Barkeeper's Friend. I'm going to do some more reading and find a method using Barkeeper's Friend.

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