>From our friends the beer brewers
(http://www.howtobrew.com/appendices/appendixB-1.html):
Appendix B - Brewing Metallurgy
B.1 Passivating Stainless Steel
A situation that often comes up is, "Hey, my stainless steel is rusting!
Why? What can I do to fix it?"
Stainless steel is stainless because of the protective chromium oxides on
the surface. If those oxides are removed by scouring, or by reaction with
bleach, then the iron in the steel is exposed and can be rusted. Stainless
steel is also vulnerable to contamination by plain carbon steel, the kind
found in tools, food cans, and steel wool. This non-stainless steel tends to
rub off on the surface (due to iron-to-iron affinity), and readily rusts.
Once rust has breached the chromium oxides, the iron in the stainless steel
can also rust. Fixing this condition calls for re-passivation.
Passivating stainless steel is normally accomplished in industry by dipping
the part in a bath of nitric acid. Nitric acid dissolves any free iron or
other contaminants from the surface, which cleans the metal, and it
re-oxidizes the chromium; all in about 20 minutes. But you don't need a
nitric acid bath to passivate. The key is to clean the stainless steel to
bare metal. Once the metal is clean (and dry), the oxygen in the atmosphere
will form the protective chromium oxides. The steel will be every bit as
passivated as that which was dipped in acid. The only catch is that it takes
longer-- about a week or two.
To passivate stainless steel at home without using a nitric acid bath, you
need to clean the surface of all dirt, oils and oxides. The best way to do
this is to use an oxalic acid based cleanser like those mentioned above, and
a non-metallic green scrubby pad. Don't use steel wool, or any metal pad,
even stainless steel, because this will actually promote rust. Scour the
surface thoroughly and then rinse and dry it with a towel. Leave it alone
for a week or two and it will re-passivate itself. You should not have to do
this procedure more than once, but it can be repeated as often as necessary
----- Original Message -----
From: "James Barrett" <jamesbrt@mindspring.com>
To: <tigers@autox.team.net>
Sent: Tuesday, December 04, 2001 3:51 PM
Subject: SS trim Rust-NOT
> Folks,
> Received a bunch of mail about non Tiger related
> subjects, and a few with questions about my Tiger. Is there
> one Tiger Person who can answer my question about pickeling
> or passivating my SS after I have buffed it?
> James Barrett Tiger II 351C and others
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