Ask The Brewmasters

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots. 
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


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Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
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Depending on the size of the vessel you may be able to polish and pickle the rust spots.  You will obviously need to follow confined space entry rules, and be very cautious when working with pickling paste.  It is highly corrosive and releases noxious fumes, so this process is best left to someone with experience in pickling stainless.  If the rust spots are out of a manageable reach an aggressive passivation cycle may help.  Dana at Birko may be able to help with some chemical and passivation process protocols for this case.

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Dan Strevey
Production Manager
Avery Brewing Company
Boulder CO
(303) 440-4324
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Original Message:
Sent: 02-08-2021 15:42
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots.
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------

Michael,

  I would talk with your chemical rep.  A strong acid should be able to remove surface rust.  The issue will be if it has created pitting which will create a hard to clean surface.  Does it appear to be a film or spot rust.  After 15 years I don't think it is something from manufacturing that will have created this, but I will let smarter people than me comment on that.

------------------------------
Jeff Carter
Bell's Brewery Inc
Galesburg MI
(269) 382-2338
------------------------------

Original Message:
Sent: 02-08-2021 15:42
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots.
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------

I paid the cheap tax on equipment at Moerlein in Cincinnati. The initial savings led ownership to choose cheap and it plagued production (and brand reputation) until bankruptcy. 

These are most likely welds done without any argon purge meaning the oxygen was in the weld the whole time. You're behind the eight-ball and all efforts will satiate the external rust while the internal oxidation continues unabated. 

I cannot call time of death on the internet, but I encourage you to prepare for the worst. Anything less than that will be a miracle. 

------------------------------
Mike Wayne
Brewmaster
Boomstick Brewing Co
Corner Brook
------------------------------

Original Message:
Sent: 02-08-2021 15:42
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots.
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------

Just spit-balling ideas here, but this could be related to weld decay.  The area around a weld is known as the heat affected zone (HAZ).  When stainless is heated during welding, the alloy composition of the material adjacent to the weld is changed.  In extreme cases, the HAZ becomes so poor in chromium that the material is more or less carbon steel.  Although weld cleaning is a common practice in breweries, the pharmaceutical industry does not want color removed from the exterior of pipe/tube welds because the color surrounding the weld is an indicator of heat.  The HAZ is more susceptible to corrosion than the base material.  Could be that you have a problem that was very slow to develop.

Has this vessel ever been used for a hot application?

Cheers,
Ashton

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Ashton Lewis
National Accounts Manager
BSG Craftbrewing
Springfield, Missouri
(417) 830-2337
------------------------------

Original Message:
Sent: 02-08-2021 15:42
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots.
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------

Original Message:
Sent: 2/8/2021 3:42:00 PM
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots. 
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------

Original Message:
Sent: 2/9/2021 7:15:00 PM
From: Jeffrey Gunn
Subject: RE: Rust in Fermentors

Hi Mike - Polish out the rust spots and passivate the tanks by using 5 % citric or nitric acid at 100 to 120 F for 30 minutes. Drain the tanks and let air dry overnight to form a patina. DO NOT rinse after passivating with acid.

Cheers,

Jeff.

Jeff Gunn
President & CEO
IDD Process & Packaging, Inc.
5450 Tech Circle
Moorpark, CA 93021
Toll Free: 800-621-4144
Tel: 805-529-9890
Fax: 805-529-9282
Cell: 805-444-3842
Web Site: www.iddeas.com

Original Message:
Sent: 2/8/2021 3:42:00 PM
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots. 
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------

Hi Michael,

I'd recommend that you passivate your entire system.  There may be extra cleaning involved prior to passivation; however, this will add a protective oxide layer that will prevent corrosion in your entire system.  This is usually accomplished with an acid (Nitric) and is basically a flush that runs in a loop for certain amount of time.  Your chemical rep should have the information and resources to accomplish this.  If not, you may want to contact a reputable chemical company like Ecolab, Diversey, or others.  Hope this helps.

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Joseph Allman
Owner
Flowtrend
Rockwall TX
(281) 990-8582
------------------------------

Original Message:
Sent: 02-08-2021 15:42
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots.
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------

A manual passivation of the tank should remove the rust, and create a clean new surface for you to use for many years to come. I find mannually passivating tanks at least every other year is a good practice for tank longevity. For the manual passivation process, you should clean (CIP) your tank as you normally would using a 2% to 3% caustic sollution. After rinsing thoroughly, you can run the same CIP process on the tank using a 50/50 blend of Phosphoric and Nitric acid at a 25% solution at approx. 110 to 120 degrees Farenheit for 30 minutes to an hour. After draining and rinsing you can follow your standard procedures for tank  break down and sanitizing process for the next use. Again this should remove the surface rust, and give you a nice "fresh" stainless surface to use for many more years. Please remember to be "safe" while using this acid blend at 25% it is extremely dangerous and you should certainly avoid skin and/or eye contact, and it can create a "vapor mist" that should also not be inhaled.
Hope this info is helpful. Cheers!​

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Brett Kintzer
Brewmaster
Swashbuckler Brewing Co.
Reinholds PA
(484) 755-0265
------------------------------

Original Message:
Sent: 02-08-2021 15:42
From: Michael Smith
Subject: Rust in Fermentors

Hello everyone:
We are now sitting in a position I've dreaded since we bought suspiciously inexpensive equipment from china about 15 years ago.
out of nowhere this last fermenter inspection is showing a lot of rust internally corresponding with the jackets obvious weld spots.
anyone have any ideas what can be done to combat this and effectively try to stretch more life out of this tank before its off to the scrap yard?


------------------------------
Michael Smith
Head Brewer
Eel River Brewing Co.
Fortuna, CA
------------------------------