Subject: ARRRGH!!..Rust!!

From: [email-masked] (Jeff Sweeney)
Date: Wed, 18 Aug 1993 17:47:30 GMT

Our steel apparatus is rusting! It seems one person in our lab has the
"golden touch". That, combined with high humidity, means we have a
recurring problem with rust. Today I disassembled one of our
diamond-anvil-cells (DAC) and cleaned it with Naval Jelly (phosphoric
acid+other stuff) and a ScotchBright pad. This left the steel parts
with a thin dull gray coating that seems to darken with time. Does
anyone know what this coating is? Phosphide or phosphate adhered to
the steel, or?

I am fed-up with this problem and I am looking for a solution. We
have done all we can to lower the humidity. Other suggestions have
been: a) Black oxide, b) electro-plating either nickel or chrome, c)
religious oiling, d) gun-bluing. Black oxide sounds good but I think
we would have to send the parts out to have them done. Plating would
definitely be out of house and therefore more expensive. Oiling might
work but, for convenience, we would rather keep the DAC oil-free. I'm
told that gun-bluing can be a do-it-yourself project but that it
stinks. Does anyone have experience with this process? What exactly is
the coating? Does it help protect steel parts from rust?
-- 

Jeff Sweeney		[email-masked]

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From: [email-masked] (Michael Burlage)
Date: 19 Aug 1993 04:02:16 GMT

>the coating? Does it help protect steel parts from rust?
Gun Blue is Selenium Dioxide.
It gives off fumes that shouldn't be breathed,
but does not smell terrible.
Does not work on:Stainless, Aluminum, ornon-ferrous metals.

It is more for glare-reduction than rust preventing,
My botle recomends top coating with their anti-rust oil.
The guns I use it on still rust and need perodic oiling.

-- 

"Onward through the fog"
                         - Power-Hitter

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From: [email-masked] (gary preckshot)
Date: 19 Aug 1993 20:08:40 GMT

In article <[email-masked]>, [email-masked]
> Gun Blue is Selenium Dioxide.

You're talking about the little plastic bottles of "cold blue" that are
sold to touch up real bluing.  The real stuff is a coating of black iron
oxide and other stuff induced by soaking in a chemical bath, usually hot,
usually extremely corrosive and poisonous, and usually containing sodium
hydroxide in large concentration among other nasty chemicals.

> It is more for glare-reduction than rust preventing,

Bluing has a protective effect by mechanical exclusion of oxygen by the
tight coating.  However, there are usually pin holes and oiling is
recommended.
The best bet for the original poster's query is probably anodizing or
parkerizing.

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From: [email-masked] (Harry Phinney)
Date: Fri, 20 Aug 1993 22:12:30 GMT

Jeff Sweeney ([email-masked]) wrote:
: Today I disassembled one of our
: diamond-anvil-cells (DAC) and cleaned it with Naval Jelly (phosphoric
: acid+other stuff) and a ScotchBright pad. This left the steel parts
: with a thin dull gray coating that seems to darken with time. Does
: anyone know what this coating is? Phosphide or phosphate adhered to
: the steel, or?

Yes, it is iron phosphate which adheres reasonably well to the steel
surface.  It provides a limited amount of corrosion resistance.

: Other suggestions have
: been: a) Black oxide, b) electro-plating either nickel or chrome, c)
: religious oiling, d) gun-bluing.

How about painting those surfaces which are handled?  The phosphoric
acid treatment is an ideal preparation for painting.  Not knowing what a
diamond-anvil-cell is or how it is used, I have no idea of the
practicality of this suggestion.

Harry Phinney   [email-masked]

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From: [email-masked] (Michael Burlage)
Date: 19 Aug 1993 04:02:16 GMT

-- 

"Onward through the fog"
                         - Power-Hitter

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From: [email-masked] (gary preckshot)
Date: 19 Aug 1993 20:08:40 GMT

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From: [email-masked] (Harry Phinney)
Date: Fri, 20 Aug 1993 22:12:30 GMT

: Other suggestions have