Subject: Re: Blackening steel?

From: Missout Gilles <[email-masked]>
Date: Tue, 25 Jan 1994 13:55:25 GMT

In article <[email-masked]> John De Armond, [email-masked] writes:
>This involves simply immersing the chemically cleaned steel object in 
>molten potassium nitrate (saltpeter).  As the temperature is brought up,
>the surface turns a straw color which proceeds to blue and then black.
>If you stop at the blue stage, the color will be a gorgeous deep royal
>blue not achievable any other way.  Very expensive custom guns are often
>blued this way.  
do I have to prevent the solution to come inside the barrel or there is
no problem?

---

From: [email-masked] (John De Armond)
Date: Wed, 26 Jan 94 20:00:06 GMT

>do I have to prevent the solution to come inside the barrel or there is

No.  The oxide coating is so thin as to have no effect.  You DO have to
protect the barrel if you are parkerizing.  We use a piece of all-thread
and a couple of rubber-lined steel washers.

John

-- 
John De Armond, WD4OQC, Marietta, GA    [email-masked] 
"Would you fire on US Citizens while in the process of confiscating their guns?"
    A question on a survey given to members of the U.S. counterterrorist 
    unit Navy SEAL Team Six by their commanders last September.
Mail to me may be published at my sole discretion.