Hi there-

I'm very new to metalworking and am just finishing my first big project, a city skyline silhouetted offset from a background, all comprising sheet metal steel.

To create contrast, I used an oxy-acetylene torch to heat patina my background after cleaning it with an angle grinder. The patina came out really nice, with brilliant blues and magentas.

The problem came after I threw a little Renaissance wax over the patina: all the nice colors were lost and the foreground and background basically look the same. I saw one post online that said those colors cannot be clear-coated because the optic properties are lost, but it recommended waxing.

Is there any good way to get those colors back? If I remove the wax, are the original colors hiding beneath? Or will I have to repeat the heat? In either case, is there a good way to protect the metal without losing the colors?

Thanks for any help!!

On Tue, 30 Oct 2018 03:07:52 -0700, arjunsharma33 wrote:

Hi there-

I'm very new to metalworking and am just finishing my first big project,
a city skyline silhouetted offset from a background, all comprising
sheet metal steel.

To create contrast, I used an oxy-acetylene torch to heat patina my
background after cleaning it with an angle grinder. The patina came out
really nice, with brilliant blues and magentas.

The problem came after I threw a little Renaissance wax over the patina:
all the nice colors were lost and the foreground and background
basically look the same. I saw one post online that said those colors
cannot be clear-coated because the optic properties are lost, but it
recommended waxing.

Is there any good way to get those colors back? If I remove the wax, are
the original colors hiding beneath? Or will I have to repeat the heat?
In either case, is there a good way to protect the metal without losing
the colors?

Thanks for any help!!

The colours are due to interference effects of the thin layer of oxides
on the surface. The thickness of the layer is the same order as the
wavelength of light (very VERY thin). Waxing - or clear-coating -
increases the effective thickness of the layer (or perhaps changes the
percentage of light-loss at the oxide-wax transition) and you loose the
colours.

You may be able to get the colours back by removing the wax with solvent,
but I'd guess that it won't work that well - you might rub or scratch
through some of the underlying oxide layer. Be prepared to start again
from beginning of your surface prep.

And no, I don't think you can protect it without loosing the colours.

On Tuesday, October 30, 2018 at 6:07:55 AM UTC-4, wrote:
Hi there-

I'm very new to metalworking and am just finishing my first big project, a city skyline silhouetted offset from a background, all comprising sheet metal steel.

To create contrast, I used an oxy-acetylene torch to heat patina my background after cleaning it with an angle grinder. The patina came out really nice, with brilliant blues and magentas.

The problem came after I threw a little Renaissance wax over the patina: all the nice colors were lost and the foreground and background basically look the same. I saw one post online that said those colors cannot be clear-coated because the optic properties are lost, but it recommended waxing.

Is there any good way to get those colors back? If I remove the wax, are the original colors hiding beneath? Or will I have to repeat the heat? In either case, is there a good way to protect the metal without losing the colors?

Thanks for any help!!

No experince, but here are some ideas anyway. The first thing I would try in using some paint thinner and paper towels to remove the Renaissance wax.. Should be easy to do and one experiment beats 100 conjectures. Next I would make some test plates by heating some scrap pieces And try some different waxes. Maybe floor wax and autobody wax.

The colors are from oxides. Blueing on guns is a oxide coating and rosists rusting to a degree. So maybe you do not need any additional .protection..

Dan

wrote in message
...
On Tuesday, October 30, 2018 at 6:07:55 AM UTC-4,
wrote:
Hi there-

I'm very new to metalworking and am just finishing my first big
project, a city skyline silhouetted offset from a background, all
comprising sheet metal steel.

To create contrast, I used an oxy-acetylene torch to heat patina my
background after cleaning it with an angle grinder. The patina came
out really nice, with brilliant blues and magentas.

The problem came after I threw a little Renaissance wax over the
patina: all the nice colors were lost and the foreground and
background basically look the same. I saw one post online that said
those colors cannot be clear-coated because the optic properties are
lost, but it recommended waxing.

Is there any good way to get those colors back? If I remove the wax,
are the original colors hiding beneath? Or will I have to repeat the
heat? In either case, is there a good way to protect the metal
without losing the colors?

Thanks for any help!!

No experince, but here are some ideas anyway. The first thing I
would try in using some paint thinner and paper towels to remove the
Renaissance wax. Should be easy to do and one experiment beats 100
conjectures. Next I would make some test plates by heating some
scrap pieces And try some different waxes. Maybe floor wax and
autobody wax.

The colors are from oxides. Blueing on guns is a oxide coating and
rosists rusting to a degree. So maybe you do not need any additional
..protection.

Dan

=========================
Good point. Ask a gunsmith about Color Case Hardening.

Thanks, all. I'll try some of these techniques this evening!

On Tuesday, October 30, 2018 at 5:07:55 AM UTC-5, wrote:
Hi there-

I'm very new to metalworking and am just finishing my first big project, a city skyline silhouetted offset from a background, all comprising sheet metal steel.

To create contrast, I used an oxy-acetylene torch to heat patina my background after cleaning it with an angle grinder. The patina came out really nice, with brilliant blues and magentas.

The problem came after I threw a little Renaissance wax over the patina: all the nice colors were lost and the foreground and background basically look the same. I saw one post online that said those colors cannot be clear-coated because the optic properties are lost, but it recommended waxing.

Is there any good way to get those colors back? If I remove the wax, are the original colors hiding beneath? Or will I have to repeat the heat? In either case, is there a good way to protect the metal without losing the colors?

Thanks for any help!!

writes:

To create contrast, I used an oxy-acetylene torch to heat patina my
background after cleaning it with an angle grinder. The patina came
out really nice, with brilliant blues and magentas.

The problem came after I threw a little Renaissance wax over the
patina: all the nice colors were lost and the foreground and
background basically look the same. I saw one post online that said
those colors cannot be clear-coated because the optic properties are
lost, but it recommended waxing.

Is there any good way to get those colors back? If I remove the wax,
are the original colors hiding beneath? Or will I have to repeat the
heat? In either case, is there a good way to protect the metal without
losing the colors?

My experience is that those heat-induced "temper" colors are too
fragile and ephemeral to be relied upon in any practical application.

Years ago I made some nice belt buckles, mild steel inlaid with brass.
Skipping over numerous details and difficulties, I was able to get
really nice heat-induced blues on the polished and carefully cleaned
steel, lovely contrast with the brass. But they didn't last. A
droplet of water/moisture would remove the color. Coatings changed
it. Wear removed it fairly quickly.

The blue tones created with various gun bluing techniques are
different, darker, less exciting, but far more durable. Brownell's
OxphoBlue(tm) is one I've used a lot but tends, with aging, to nearly
black.

There is a bluing technique using molten potassium nitrate reputed to
give a better/nicer color but I've never used it or seen the result.
You might research that with gunsmiths or, perhaps, makers of fancy
spurs in the US southwest.

FWIW,
--
Mike Spencer Nova Scotia, Canada

On Tuesday, October 30, 2018 at 5:38:43 PM UTC-4, Mike Spencer wrote:
writes:

To create contrast, I used an oxy-acetylene torch to heat patina my
background after cleaning it with an angle grinder. The patina came
out really nice, with brilliant blues and magentas.

The problem came after I threw a little Renaissance wax over the
patina: all the nice colors were lost and the foreground and
background basically look the same. I saw one post online that said
those colors cannot be clear-coated because the optic properties are
lost, but it recommended waxing.

Is there any good way to get those colors back? If I remove the wax,
are the original colors hiding beneath? Or will I have to repeat the
heat? In either case, is there a good way to protect the metal without
losing the colors?

My experience is that those heat-induced "temper" colors are too
fragile and ephemeral to be relied upon in any practical application.

Years ago I made some nice belt buckles, mild steel inlaid with brass.
Skipping over numerous details and difficulties, I was able to get
really nice heat-induced blues on the polished and carefully cleaned
steel, lovely contrast with the brass. But they didn't last. A
droplet of water/moisture would remove the color. Coatings changed
it. Wear removed it fairly quickly.

The blue tones created with various gun bluing techniques are
different, darker, less exciting, but far more durable. Brownell's
OxphoBlue(tm) is one I've used a lot but tends, with aging, to nearly
black.

There is a bluing technique using molten potassium nitrate reputed to
give a better/nicer color but I've never used it or seen the result.
You might research that with gunsmiths or, perhaps, makers of fancy
spurs in the US southwest.

FWIW,
--
Mike Spencer Nova Scotia, Canada

To get a thicker coating with heat, the traditional method (used a lot on guns, 100 years ago) was to heat the steel in the presence of a cyanide-based case-hardening material.

Yes, it's potentially dangerous. And it works. If you use a powder, you get the mottled colors common on Stevens rifle and many shotgun receivers.

There are other ways to do it, but I've long since forgotten what they are. Maybe a search on "heat treatment colorizing" or something like that will bring it up

--
Ed Huntress