Phosphoric Acid does not re-passivate Stainless Steel. - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > Equipment/Sanitation > Phosphoric Acid does not re-passivate Stainless Steel.

Reply
 
Thread Tools
Old 03-13-2009, 07:12 PM   #1
GilaMinumBeer
Half-fast Prattlarian
HBT_LIFETIMESUPPORTER.png
 
GilaMinumBeer's Avatar
Recipes 
 
Jan 2008
Posts: 59,188
Liked 7672 Times on 6268 Posts



I was just told this.

I had technical help on the phone as I was asking about chemical compatibility with various materials regarding 5 Star Acid #5 and in the conversation this statement was made. ".....phosphoric acid does not re-passivate SS it's the Nitric Acid that re-passivates...."

I mentioned that I was taking this info from Palmers Metallurgy appendice and was told that "...Palmer is making corrections...."

I have also read that Oxalic Acid (BKF) re-passivates and now I wonder if that is true or not.

 
Reply With Quote
Old 03-13-2009, 07:59 PM   #2
conpewter
HBT_SUPPORTER.png
 
conpewter's Avatar
Recipes 
 
Nov 2007
East Dundee, Illinois
Posts: 5,109
Liked 53 Times on 48 Posts


Well I think BKF does re-passivate. I cut the handle and 'ears' off a stainless steel strainer (that sits in a pot) and it is now my hop-stopper. I cut them off with a dremel, scrubbed it with BKF, waited 10 minutes then washed it off, put it in the pot and did a 60 minute boil. I didn't see any rust in post-cleaning.

It should also be noted that I used a grinding disk on a dremel, not a saw. The saw might leave regular steel in the cut and promote rusting of the stainless.
__________________
"People should not be afraid of their governments. Governments should be afraid of their people." - V

Primary: Nothin
Secondary: Shady Lord RIS, Water to Barleywine, Pumpkin wine, burnt mead
Kegged: Crappy infected mild
Bottles: Apfelwein, 999 Barleywine, Oatmeal Stout, Robust Porter, Robust smoked porter, Simcoe Smash

 
Reply With Quote
Old 03-13-2009, 09:32 PM   #3
kladue
Senior Member
HBT_LIFETIMESUPPORTER.png
Recipes 
 
Dec 2006
Turner, Oregon, Oregon most of the time now
Posts: 2,305
Liked 53 Times on 47 Posts


50-50 mix of citric and ascorbic acid in water, heated to 180 deg. F and circulated, this is the method of choice these days in the food and pharmaceutical piping system passivation. Solution is circulated until soluble iron content remains constant which is the signal that the passivation is finished.

 
Reply With Quote
Old 03-13-2009, 11:31 PM   #4
Beerrific
 
Beerrific's Avatar
Recipes 
 
Mar 2007
Georgia
Posts: 5,562
Liked 55 Times on 47 Posts


Yes, oxalic acid will work. Take a listen to this: Brew Strong, Metals. Palmer spends a bit of time talking about how to handle stainless.

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
pH: Acidulated malt vs phosphoric acid Piotr Recipes/Ingredients 7 09-29-2016 01:05 PM
is there any way to tell if something is Stainless Steel Grinder12000 Equipment/Sanitation 25 05-12-2010 01:44 PM
Phosphoric Acid Taste Threshold Question Spine All Grain & Partial Mash Brewing 2 02-22-2009 04:05 PM
Phosphoric Acid and Chloramines GilaMinumBeer Equipment/Sanitation 2 10-10-2008 02:13 PM
food-grade phosphoric acid conpewter Soda Making 2 09-18-2008 08:37 PM


Forum Jump