Patina Demo by Shawn McCurdy,
[Matt Weber] 7:12 pm: Ok, Lets get started
[Matt Weber]7:12 pm: ok here goes
[ShawnM] 7:13 pm: ok folks, we're going to get started! Welcome to the 4th monthly Demo on the Metal Artists Forum.
[ShawnM] 7:13 pm: Introduction
what is a patina? Patina in general means a change to the surface of
metal, wood, or other material, because of age, usage, or exposure to
the elements. In this demo, we'll talk about intentionally causing a
metal patina by using chemicals.
I'll cover some general
information on preparation, application, and protection that applies to
all patinas, and then I'll talk about some specific patinas that I like
There are thousands of patinas. You can mix chemicals
to make your own or buy them ready-made. Tonight I'll talk mostly about
commercially-available products' Solvent Dyes, Universal Patinas, Vista
Patinas, Traditional Patinas, and Metal Coatings - all of which are
available through Sculpt Nouveau (www.sculptnouveau.com). I'll also
talk about some ways to make rust, and highlighting with Gilder's
Paste. Although all of these patinas are for steel, most of them can
also be used on other metals as well.
[ShawnM]7:15 pm: I know a lot of you like to leave your metal bare, or use a
simple darkening patina, or sometimes you get adventurous and go for
Japanese Brown? nothing wrong with those, but my goal tonight is to
inject some color into your life! Hopefully next time you get to the
finish stage you'll at least consider trying a colorful new technique.
Even just a touch of color on an otherwise plain piece can make a big
Patinas can be categorized as acid or non-acid. This
distinction is important when you're working with any ferrous metal
(ferrous means it contains iron). Acid-based patinas have a chemical
reaction with the metal. They may make a beautiful color on copper,
brass, or bronze but can cause rust and pitting on steel. Sometimes
that may be what you want, sometimes it may not!
patinas can be thought of as dyes or paints for metal. They contain
pigments and Don't react with the metal surface so Don't cause rust or
pitting. They range from transparent to opaque.
[ShawnM] 7:16 pm: Disclaimer
are chemicals - in some cases, very potent ones. Always exercise care
and make sure you follow precautions with regards to storage,
ventilation, personal protection (skin, eyes, lungs), and disposal of
patinas and the other chemicals that you'll use.
products may not always be labeled with safety information. If you're
not sure, do your research before using them. I'm not going to present
safety cautions for everything in this demo, nor do I take
responsibility for any mishaps. Use of any of the information presented
tonight is done at your own risk.
My intention is that this demo
will serve as a basic guide to working with patinas. It's geared more
towards the beginner and intermediate user, but hopefully you experts
will learn something too. There are no doubt a lot of other techniques
that work, and there are a whole lot of patinas that I am not going to
talk about. Further experimentation is left as an exercise for the
I live in Florida and work in our barn, which is not
climate-controlled. My demo includes some advice on dealing with
moisture from humidity, since I have to deal with that all the time.
You may not have the same issues where you live.
Let?s get started!
[ShawnM] 7:18 pm: Exactly What Will It Look Like??
exact result you'll get depends on the particular piece of metal, what
kind of prep and cleaning you?ve done, temperature, humidity, and other
factors too numerous to list. It's difficult if not impossible to get
exactly the same result every time.
If the look is critical, do
a test run on a scrap prepared in the same way or on an inconspicuous
part of your piece. The clear coat that you use may affect the way the
patina looks, so include it in your test run too.
Just keep in
mind that even if it doesn't turn out the way you expected, you might
love it anyway! that's called a ?Happy Accident?.
[ShawnM] 7:19 pm:
Here are some of the supplies that I use when working with patinas.
Brushes of various sizes
spray bottle (chemical resistant)
shop towels, paper towels (I use Scott Shop Towels a lot, they are
throwaway towels that are more like cloth than regular paper towels)
scotch brite pads
Permalac (a good clear coat finish)
air compressor with attachments
[ShawnM] 7:20 pm: General Finish Preparation, Application, & Protection
patina result will be more uniform on a surface that's sanded or
blasted to a consistent finish as opposed to one that has a lot of
variation. However, most patinas will not bond well to a real shiny
surface so Don't go overboard with the polishing. A nice satin finish
The metal surface should be completely free of
grease, dirt, dust, and residue from surface prep before starting your
patina. I use an acid-based metal cleaner called Industrial Metal
Supply (IMS) Cleaner/Degreaser. Sometimes it leaves a whitish residue
which can be removed with a scotch brite pad.
Clean, bare steel can start to rust immediately so after you clean your piece, the sooner you start your finish the better.
your final cleanup is done, try real hard to keep clean gloves on your
hands throughout the patina and clear coat steps. Even when your hands
are clean, the natural oils from your skin can transfer to the metal.
[ShawnM] 7:22 pm: During:
can apply patinas with paint brushes, sponges, rags, cotton balls,
sprayers, air brushes - the best advice I can give you is to experiment
with different applicators until you find something that works for you.
There is no right or wrong.
I usually pour a little of the
patina into a glass and apply it from there. That way I don't risk
contaminating the original container with anything.
position your piece so that you are applying the patina on a horizontal
surface in order to get a good even coat and minimize dripping. Drips
can be a design feature though, so if that's what you're after, go for
Patinas can be applied hot or cold. Cold patinas are applied
to unheated metal and hot patinas are applied to heated surfaces, about
200 degrees. There are some patinas which can be done either hot or
cold. For those patinas, generally a hot application will result in a
darker and more even color while cold will give you more variation and
a lighter shade.
[ShawnM]7:23 pm: The drying time will vary depending in part on temperature and
humidity. With non-acid patinas you can usually hurry up the drying
process with a heat gun set on low, but acid-based patinas often need a
slower drying period in order to activate properly.
they're dry, acid-based patinas will need some time to develop fully -
anywhere from a couple of hours to a day or more. Development is a
chemical process during which the appearance of the patina will change,
sometimes quite dramatically.
Some patinas, especially rust
patinas, may not want to quit developing when you're ready for them to
quit. There are a couple of things you can use to help halt the patina.
These are known as ?stop outs?.
One option (which I haven't
tried but is sold by Sculpt Nouveau) is potassium dichromate, which is
a toxic chemical that's applied in a very dilute solution of ¼ teaspoon
to 16 oz. distilled water.
Another choice (which I use
frequently) is acetone. It can be sponged on or sprayed from a
chemical-resistant spray bottle. Acetone also has the added advantage
of drying the surface really well, an important step which I'll talk
[ShawnM] 7:25 pm: After:
are various protective finishes that you can use. A coat of wax or a
hot oil finish may work well enough for an indoor piece. I usually
clear coat so that's what I'll talk about.
After your patina
is done, wait about 12 hours before clear coating, or however long the
specific patina instructions tell you to wait. Make sure the surface of
your piece is completely dry before applying the final protective
finish. Some patinas really hold a lot of moisture. In Florida It's
always an issue. Use a heat gun to drive any moisture off the surface,
and if the patina can handle an application of acetone, apply it also,
then clear coat as soon as the acetone dries.
can act as a solvent for some patinas and will remove them, so be sure
and test in an inconspicuous place before you apply acetone to any
I spray my pieces with a good quality lacquer &
then wax them. I generally use Permalac, which is supposed to be one of
the best and most durable especially for outdoor use. Permalac comes in
liquid form in various sized containers. You can also get it in spray
cans for easy use on small projects or touch-ups.
[ShawnM]7:26 pm: I use a spray gun that runs off my air compressor. In humid
climates, It's a good idea to dry the air before it goes through your
sprayer. There are 2 methods I use.
You can attach one of
these little dessicant dryers between your spray gun and air source.
The filter starts out blue and turns pink as it absorbs moisture. When
completely pink, It's time to change to a new one. These can be bought
at Harbor Freight.
An alternate method is to run your air line
through a drying filter like this Motor Guard filter. These filters are
also great to use with your plasma cutter or blast cabinet too. Motor
Guard filters can be purchased at any number of online stores.
[Matt Weber]7:27 pm: one more little bit
[ShawnM]7:27 pm: When sprayed, Permalac should be thinned with about 20%
xylene. I apply 2-4 coats of Permalac, waiting about 2 hours between
The last thing I do is to apply 1-2 coats of wax. I
usually heat the surface with the heat gun and use a small brush to dab
on the wax. It will melt from the heat and get into cracks and
crevices. Buff with a soft rag after it hazes up. Wax is just another
layer of defense. It won?t hold up forever so should be re-applied once
in a while (just like you wax your car periodically).
I'm going to talk about some specific patinas.
[ShawnM] 7:30 pm: Solvent Dyes
Type: Non-Acid, solvent-based
Apply To: Any metal
Application temp: Cold
Cleanup: Denatured alcohol
dyes provide bright, transparent color. They come in a very
concentrated form and are thinned with a special dye thinner. Permalac
can also be used as a solvent dye thinner. Denatured alcohol is used
dyes are transparent except for the white dye, which can be mixed into
the other colors to make them more opaque. Solvent dyes do not develop
(change after application) and do not darken or change color when a
clear coat is applied. What you see is what you get! Because they are
transparent, anything you see on the surface of the metal (scratches,
discoloration, etc.) will show right through.
Solvent dyes will not bind well to a real shiny surface so be sure to leave a little texture.
Make sure to wear gloves -these dyes work on skin just as well as metal. Nothing like having multi-colored fingers!
by mixing dye with thinner. The proportions are a matter of
experimentation. You can start out with 6-8 drops of dye to ½ oz. of
thinner. Try it and adjust from there. I like my colors pretty
saturated, so I tend to use more dye.
[ShawnM]7:31 pm: I use a sponge or brush to apply solvent dyes. In either case,
you can brush or stipple (dab) the thinned dye onto your metal surface.
The dye will tend to self-level, creating a fairly uniform application.
Being solvent based, it dries pretty fast. If you want more streaks or
splotches, keep working it with your sponge or brush as it is drying to
?bunch? it back up. If you want real even coloration, try using an air
You can re-apply over the first coat while It's still
somewhat wet or after It's dry. You can create a lot of different
effects by layering different colors on top of each other. If you Don't
like the effect you got, It's pretty easy to change or remove what
you?ve done using a brush or rag wet with dye thinner.
samples show some of the colors you can get with Solvent Dyes. Every
other sample is a single color. In between are the two colors layered
on top of each other. The last set shows how adding white makes the
colors more opaque.
[ShawnM]7:33 pm: Let the solvent dye application dry for about 12 hours before
clear coating. Acetone acts as a solvent - DO NOT apply acetone to dry
the surface prior to clear coating it. Stick with a heat gun.
Permalac is a solvent dye thinner, there is a possibility that your dye
may sag or run when you clear coat with Permalac. It helps a lot of you
keep the surface you're spraying horizontal. Applying a few light coats
also will help rather than applying a full wet coat right away.
dyes can also be applied over other patinas. You can even add a little
solvent dye to Permalac to get a transparent color in your clear coat.
are some pieces that I colored with solvent dyes. You can see some of
the different looks you can get by varying the proportion of dye &
thinner and by applying it with different methods. For clear bright
color and variety in application, I haven't found anything that matches
[ShawnM] 7:37 pm: Dye Oxides
Type: Non-Acid, water-based
Apply to: Any metal
Application Temp: Hot or Cold
is another set of metal dyes that you can get from Sculpt Nouveau
called Dye Oxides. I'm not going to talk about them a whole lot, but
they are water-based as opposed to solvent-based and come pre-thinned,
ready to use. I Don't use them as much as Solvent Dyes because being
they Don't give me as the same versatility and effects, but they are
another option for transparent color. They can be applied over other
patinas or even mixed into them. Here's a quick look at the Dye Oxides:
[ShawnM] 7:38 pm: Universal Patinas
Apply to: Any metal
Application temp: Hot or Cold
patinas are non-acid so they Don't cause rust on ferrous metals. They
do not develop or react so the color stays the same after application.
They are more opaque than Solvent Dyes. They can be applied either hot
or cold - these samples were done hot, which is the recommended
technique for application over bare metal.
[ShawnM]7:39 pm: Universal Patinas are something like paint, except they can be
applied directly to metal with no primer. If applied lightly, the metal
will show through but if applied heavily they will cover the surface.
Universal patinas can look somewhat chalky and bright initially but
when clear coated the color will deepen a bit.
They also work
well when combined with other patinas or layered over darker patinas.
You can get some nice effects by putting Vistas and Universals next to
each other. Here's some Universal patinas paired with Vista Rust on the
garden bell I made. It's a little over the top but you get the idea ;o)
[ShawnM] 7:40 pm: Vista Patinas
Type: Acid & Non-Acid combined
Apply to: All metals except Aluminum
Application temp: Cold
Vista patinas contain both acid and non-acid components which Don't mix
well (like oil and water) and result in a marbleized effect. They react
to the metal and will develop over a number of hours.
used on steel, the acid part makes rust and the non-acid part makes a
color. Think of it as different shades of rust. On other materials
(copper, brass, bronze) they make green plus a color. There is also a
special Vista green made just for steel which only makes a very small
amount of rust compared to the other Vista colors. It looks on steel
more like the normal Vistas look on copper, brass and bronze. It's one
of my favorites.
[ShawnM]7:42 pm: Vista patinas are essentially a coating and will obscure the
surface completely. On steel you will also end up with nice texture
from the rust. Here's a closeup of Vista Rust texture.
sure you mix the Vista patina before you start, and stir it
occasionally during use to make sure you're getting both components of
the patina. I generally use a brush and dab it on. You can reapply if
needed but I usually get good coverage from one coat. Allow about 12
hours for development. These Vistas were photographed the day after
application and before clear coat.
[ShawnM]7:43 pm: The Vista patinas literally draw moisture from the air. If
left in a real humid place, you may find the surface dripping wet after
a few hours. If you live in a humid location It's best to keep your
piece in a climate-controlled place until you get it clear coated.
Otherwise the rust just might take over!
Before I clear coat, I
heat the surface with a heat gun then apply acetone to help halt the
rust and get it good and dry. Then clear coat as soon as the acetone
dries. I recommend several full coats of Permalac over Vista patinas.
Note that the color will darken when the clear coat is applied.
Other patinas can be layered on top of Vista patinas for even more variation.
[ShawnM] 7:44 pm: we will now pause to let you ask any questions you might have.
[ShawnM 7:46 pm: If everyone's caught up and there are no questions I'll continue, OK?
[Stretch] 7:47 pm: OK
[Devine] 7:47 pm: Regarding the Vista Patinas: Were these
www.metalartistforum.com/demos/01-04-07/app-vista-patinas.jpg applied on rusted steel?
[ShawnM] 7:47 pm: Traditional Patinas
are a bunch of patinas that are lumped into the ?traditional? group.
They are, as the name implies, are traditional and usually old
formulas. If you have a chemical supply place handy, you can probably
Google a recipe and concoct many of them yourself.
Traditional Patinas are acid-based and will just rust if used on
ferrous metals. However, here are some which work really well on steel.
[ShawnM]7:49 pm: Sorry Devine, I didn't see your question. Those were applied
to clean steel. The rust developed overnight from the acid component of
[Devine] 7:49 pm: Thank you ;)
[ShawnM] 7:50 pm: You're welcome! Now I'd like to give you some info on a few of the Traditional Patinas that I like to use.
[ShawnM] 7:50 pm: Japanese Brown
Apply to: Any metal
Application temp: Hot or Cold
Brown produces a rich deep brown patina. For more consistent color, the
surface should be sanded smooth (blasting works great) and heated prior
to application. For more variation, do less surface prep &/or apply
Brown is perfectly clear before application. It's also very watery and
will tend to drip and puddle. I find it easiest to use a rag for
You can re-apply Japanese Brown in multiple coats
to get the depth of color that you want. I usually recoat quickly as
soon as the previous coat is dry.
[ShawnM]7:51 pm: Allow about 12 hours after the last coat before you clear
coat. Heat the surface with a heat gun to chase off any moisture, and
then spray with acetone. Clear coat immediately when the acetone dries.
Japanese Brown will darken and get very rich looking when you clear coat it.
Brown is a favorite for many people here on the forum. Here are some
great examples of Japanese Brown finishes created by other people.
Japanese Brown on The Chair (synapuscapus):
Japanese Brown on iron bowl with highlights of green & yellow Universal patina (Grizz):
[ShawnM] 7:52 pm: Traditional Tan
Apply to: Any metal
Application temp: Hot or Cold
tan can be used on any metal. It can cause a little rust on steel but
creates a really nice color. It looks beige in the bottle, but darkens
to a pretty tan/rust color. It's applied cold and you can let it
develop anywhere from a couple hours to a day. It is quickly becoming a
favorite of mine!
Traditional Tan looks especially good when paired with greens. Here it is layered with Universal Verde.
[ShawnM] 7:54 pm: Birchwood Casey Products
Application temp: Hot or Cold
Birchwood Casey (BC) company makes a number of metal darkening
products. You can sometimes find their products in sporting goods
stores for use in restoring the finish on guns (usually called ?gun
BC products come in both liquid and gel form. The gel
is easy to use on small projects and on vertical surfaces. Just rub or
brush it on, then after it sits for a minute or two, the residue can be
rinsed or wiped off.
Generally the liquid versions are diluted
with water. Depending on where you purchase the liquid, it may come
pre-diluted so check the instructions. The liquid can be used in a
sprayer or ragged on, or the piece can be completely immersed.
[ShawnM]7:55 pm: They can be applied hot or cold. A hot application makes the
color darker and results in a more even application. You can also
burnish BC finishes with a scotch brite pad or steel wool after they
dry to give them a nice, mellow look and produce highlights on raised
areas or corners.
These products can be used alone or under and over other patinas.
BC products are meant for use on one type of metal or a group of
metals. BC has products that work on steel, brass, copper, bronze,
aluminum, nickel, silver, tin, and pewter. For future reference, you
can find descriptions of their products on this page:
[ShawnM]7:56 pm: Here are three BC products that I like. Note that the name
does not always necessarily describe the color it produces. They are
all dark, but may have undertones of blue, purple, grey, brown, or
bronze, depending on the temperature, particular piece of metal,
surface prep, etc.
Blue Paste Gun Blue is an easy-to-use gel for iron and steel that is
especially good for smaller projects or on vertical surfaces. Applying
it cold can result in a lot of color variation and almost a wood grain
Brown comes in either liquid or gel. Although this is described as
being for bronze, brass, or copper, it seems to work OK on steel also.
aka Presto Black comes in either liquid or gel and is used on iron and
steel. It produces a dark grey or black color but can also have some
color variations, with blue and purple showing up sometimes.
[ShawnM] 7:57 pm: Anyone have any questions about this last part?
[Matt Weber] 7:58 pm: Awesome demo so far Shawn. TONS of info
[ShawnM] 7:58 pm: Thank you! :)
 7:58 pm: Yes, tons of info. I'll be reviewing this again in the future. Thank you!
[Stretch] 7:59 pm: Makes me start to think of doing some different finishes, Thanks
[Metal Artist Forum]: duck has left at 7:59 pm
[Metal Artist Forum]: duck has entered at 7:59 pm
[ShawnM] 7:59 pm: Cool, that was the idea!
[ShawnM] 8:00 pm: If there are no further questions I'll keep going...
[Devine] 8:00 pm: Thank again!
[ShawnM]8:00 pm: Other Traditional Patinas can be used on copper, brass, and
bronze. If you want to experiment with these on steel, the best way to
do that is to use one of the Metal Coatings over your steel, then apply
the traditional patina of your choice to the Metal Coating.
Coatings are kind of like paints that contain metal powder. They come
in various colors, including bronze, brass, copper, pewter, silver, and
iron. The idea is that the patina reacts to the metal powder in the
coating the same as if you applied it to a solid piece of metal.
original Metal Coating A sealed as it dried, so that a patina had to be
applied while it was still wet. Metal Coating B was developed next ? it
does not seal so the patina can be applied while the metal coating is
either wet or dry. Metal Coating C is the latest. It is a multi-part
coating and dries to an extremely hard surface. I?ve only used the
Metal Coating B type.
[ShawnM]8:01 pm: You have to prime steel with a metal primer before applying
the metal coating. That ?insulates? the steel from the dissimilar metal
and keeps any corrosion from happening. You can also use texture paint
in between the primer and the metal coating to give the surface a
rough, cast look.
Metal coatings are applied cold. Two coats are recommended.
an example of a steel box with some metal coating and traditional
patina added for decoration. The box was made using the technique that
Dan described in his box demo. I highlighted some areas on the lid
using (in order) primer, texture paint, 2 coats of Brass Metal Coating
?B?, and Powder Blue traditional patina.
[ShawnM] 8:03 pm: Rust Patinas
As mentioned before, Vista and many Traditional patinas will make quick rust on ferrous metals.
Florida, my lazy method is to put the piece outside and come back in a
month or so. You can help the natural rust form by using an
accelerator. Here are a couple of recipes to accelerate natural rust
that Matt has provided on the message forum:
Matt?s Ferric Nitrate Patina: take a lump of ferric nitrate, put it in a spray bottle, add water, shake and spray.
Magic Vinegar and Salt Patina (sounds like something you would eat): 16
oz bottle of Hydrogen Peroxide, (the kind from the drug store) about a
cup of white vinegar, and about four teaspoons of salt. Make sure the
metal surface is good and clean, heat it up (sizzling is a little too
hot), and apply. Re-apply until you like the result.
Note that rust will generally darken when you clear coat it.
[ShawnM] 8:04 pm:
colored wax-based pastes can be used alone or as highlights over other
patinas. Most of them are metallic. They come in small tins and tend to
dry out over time, but can easily be thinned with mineral spirits.
Application can be done with a rag or brush, or with your fingers.
Gilder's paste can be applied under or over a clear coat.
are many colors that are available and I Don't have them all. The
lighter colors show up best against a dark surface, and the darker ones
look best on a lighter surface. Here are the ones I have ? the light
ones over bare steel and the dark ones over Presto Black.
[ShawnM] 8:05 pm: How do I know what to use???
There are a lot of choices when it comes to patinas.
Here's a simple flowchart to help you with the basic decisions.
are fun! Don't be intimidated by the process but follow good safety
procedures. Try it out on a test piece for practice or to preview the
result. If you Don't like the way it turns out, layer another patina on
top ? you may invent your own unique finish!
[ShawnM] 8:08 pm: Here are sources for some of the things I've talked about:
[ShawnM] 8:08 pm: Commercial Patinas:
Manufacturer: Peacock Labs
Manufacturer: Industrial Metal Supply
Gilder's Paste sources:
Architectural Iron Design
http://www.sciencecompany.com/patinas/index.htm (includes a good list of chemicals used in patinas)
The Colouring, Bronzing, and Patination of Metals by Richard Hughes & Michael Rowe
The process of applying a patina is called patination. A piece with a
patina on it is said to be patinized. A person who produces patinas is
[ShawnM] 8:10 pm: Are there any questions about anything that I've covered tonight?
[Matt Weber] 8:11 pm: No. You did an excellent job with lots of detail!
[duck] 8:11 pm: Way to much for a senior citizen to digest in one night. Wonderfully done Shawn..it should be published
[Matt Weber] 8:11 pm: :clap: