[TheForge] RE: Putting some blue color in iron

Fri Mar 15 09:45:00 2002

> ----- Original Message -----
> From: "H and P Foster" <[email protected]>
> To: "the forge" <[email protected]>
> Sent: Friday, March 15, 2002 11:49 AM
> Subject: [TheForge] Putting some blue color in iron
>
>
> > One of my clients wants me to put some blue color in the chain I am
making
> > for him to match some other material he has.  I have tried heating till
I
> > see the blue color and then quenching in oil, but the color mostly goes
> away
> > by the time the piece cools.  What is the secret to getting a real nice
> blue

Harry, I often use heat to blue my ML parts. It does help to have the piece
polished.  For a bright temper blue I use a torch to slowly and evenly bring
the piece up to 575 or so. As the piece goes through the color changes, I
carefully apply heat where needed to provide an even color. When it gets to
bright purple you can often remove the heat and the piece will continue to
change to a blue, and then bright blue, and then you have to quickly stop it
when it looks right by quenching. A more durable blue can be had by soaking
the piece at the temp. required to get the bright blue. You have to be
careful not to exceed that temp. or the bright blue will change to a dull
greyish blue.
Another heat blue I use is a charcoal blue. This can be had by soaking the
piece at a black red heat in charcoal for an hour or so. I don't know
exactly what temperatures I am achieving when I do it, but would guess
around 1000-1100 degrees. On the cooler end you will get a very nice mottled
blue/gray look, on the hotter end of a black red heat you will get a very
fine mottled dark blue. This charcoal blue is a lot tougher than a temper
blue. Here is a couple pics of a charcoal blue barrel on a rifle I built a
couple months back.

http://users.ez-net.com/~northwoods/DSCN0137.JPG
http://users.ez-net.com/~northwoods/DSCN0142.JPG
http://users.ez-net.com/~northwoods/DSCN0151.JPG
http://users.ez-net.com/~northwoods/DSCN0138.JPG

T. Clark
Mountain, WI