[TheForge] Putting an oxide finish on mild steel?

[Woolley]

Greetings,

When I discovered how beautiful an effect I could get with an acetylene
torch on polished (it must be polished, bright, as in no mill scale, not
just wire brushed) mild steel ( purples,greens blues) I thought I was going
to be able to use this finish for all kinds of decorative stuff ( panels,
furniture) until I tried to fix it.  I found that if I sprayed a lacquer or
any kind of clear it would go like an ice blue color time and again. I have
managed to preserve the oxide colors with oils but these never dry so the
pieces can't  really be handled too well (not a good selling point for
furniture).  I have pretty much abandoned this finish. My two cents.

Regareds,
Bill Woolley


----- Original Message -----
From: "Justin Fellenz" <sunironworks at yahoo.com>
To: "Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Saturday, March 12, 2005 7:59 PM
Subject: Re: [TheForge] Putting an oxide finish on mild steel?


> I've been playing with this effect on the damascus wedding ring I made
> myself. I found that if I heat it over the gas stove to where I just
> see it darken and then take it off and let it cool slowly in air, I get
> a progressively darker finish--it seems that being in the flame (I
> guess like in a gas-welding environment) keeps the metal protected
> somewhat..once I take it out of the flame the oxides seem to get darker
> over time than they do in the flame. I haven't been able to come up
> with anything reproducible either, but I haven't tried--I'm just
> noodling. Maybe a known time in a known flame and then a known cooling
> time would yeild predictable results. It also seems to work better the
> more polished the surface.
>
> Justin.
>
> --- Steve Smith <sos at alum.mit.edu> wrote:
> >
> >
> > Aaron Stavens wrote:
> >
> > > I had another different piece of sheet steel I had welded on with
> > E6013.
> > > I had baked it in my kitchen oven and, unintentionally, it acquired
> > a
> > > dark blue color with purple and copper highlights. There is also a
> > nice
> > > iridescence in places. My friend saw this and liked it. So, I'm
> > trying
> > > to achieve a similar effect on the bracket.
> > >
> > > I figured I would buff the bracket with a wire wheel and bake it in
> > the
> > > oven like I did with the previous piece. The baking didn't go so
> > well.
> > > All I could achieve was a very light translucent blue even after
> > hours
> > > in the oven. I assume my oven simply isn't hot enough, but I'm
> > already
> > > running it at the maximum of 550F. I also tried heating the bracket
> > with
> > > my welding torch. I achieved a whole rainbow of colors, but I
> > couldn't
> > > seem to control the colors I achieved.
> >
> > You're right in describing this as an oxide finish. What happens is
> > if
> > you have a thin enough layer of oxide, light hitting the surface will
> >
> > interfere with itself (this thin the oxide is essentially
> > transparent).
> > This reinforces some wavelengths and reduces others, which leads to
> > colors.
> >
> > I think what you have might be too thick a layer of oxide, giving you
> >
> > the translucent blue. Try running it at several lower temperatures
> > (400F? 450F?) and see what happens. Make up some test pieces and take
> >
> > them out of the oven at different times.
> >
> > You might also try heating one end of a shiny piece of metal with a
> > torch. The colors "run" along the rest of the piece really quickly
> > when
> > you get to the right temperature. It may be tricky to control, even
> > in
> > an oven.
> >
> > Steve
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