Blue patina with amonia and salt

Jewelry Discussion
1

I’ve tried this on copper a couple of times… it looks gorgeous but
as soon as you touch it it flakes off… How do you get the amonia
patina to stick or actually colour the copper and not just sitting
on the surface like an unbonded powder?

Lynne

2

To keep a patina from flaking off, try spraying with a clear spray
intended for CARS. You have to do this outside. Try some samples out,
spraying once, or several times. I learned about this spray from
Alchimia in Florence Italy.

Roxy

3 
I've tried this on copper a couple of times... it looks gorgeous
but as soon as you touch it it flakes off... How do you get the
amonia patina to stick or actually colour the copper and not just
sitting on the surface like an unbonded powder?

I have done some experimenting with this type of patina, though I
mostly did it on brass rather than copper. I would expect much the
same results on copper.

I concluded that the longer it takes to develop the patina, the
longer it stays on. When I did it by putting the metal object in a
closed plastic container (a Star Wars lunchbox, if you must know)
along with-- but not IN-- a small dish of ammonia, and left it for up
to a few days, the patina was so durable I could steel wool it
without removing the color.

It didn’t occur to me before, but it may also have helped that I was
etching areas, leaving the resist on, and patina-ing the etched
areas, then removing the resist. You could try a light etch with
ferric chloride before treatment to see if it helps.

I also had good results burying pieces in wood chips moistened with
ammonia or ammonia and salt, but in the last few weeks I’ve been
trying this with students, and the results have been mixed (no, I
didn’t bury the students in wood chips. Ah, English!) One thin piece
of copper left for a week dissolved into nothing but a bright blue
layer of oxide. Pretty blue, though!

Fortunately, all the materials for these trials-and-errors are
cheap.

Noel

4

I’ve similar success with my usage of the same chemicals. But that
said, I stumbled upon by pure accident an almost florescent line
green patina that acts the same way kind of powdery but you can’t
blast the color off short of heating to annealing temp and pickling
in fresh pickle after scrubbing as much of the patina off with a wire
brush as you can. I was using swimming pool acid to pickle. My
daughter used stainless steel tongs to grab a few items out of it. I
didn’t know she had contaminated the pickle. Sparex and swimming pool
acids are different. It is the only thing I can think of that makes
sense in this. So when I read your question I was wondering if the
chem wiz’s here (my chemistry is 20 years out of date) can figure out
if that is a route by which to experiment and make a blue patina that
would stick. Would starting with a warm ammonia bath work as opposed
to acid? Would copper salts help to encourage the blue? Or did I just
add another question to yours?

Aggie

5

As with a wide range of patinas a surface sealant is required. In my
work with this patina I know of no way to avoid any of the surface
’grain’ yet still have that wonderful color…but then I’m not patina
trained…still learning.

John

6

I found that patina still flaked off even after spraying. Good
suppier for patinas

7 
I also had good results burying pieces in wood chips moistened
with ammonia or ammonia and salt, but in the last few weeks I've
been trying this with students, and the results have been mixed

I recently learned that sunshine helps. I put some pieces of copper
in patina solution in a studio cabinet and they didn’t develop nice
colors. I did my next batch, gave them an afternoon in the sun and
did not put them in the cabinet, the results were bluer.

Elaine
CreativeTextureTools.com

8 
in the last few weeks I've been trying this with students, and the
results have been mixed (no, I didn't bury the students in wood
chips. Ah, English!)

I must thank Noel for the laugh!!! As I teach, I really loved the
image that came to mind with this lol! The tips on patina were nice
too :wink:

Beth Wicker

9

Elaine- Was it the UVs from the sun or the heat from the sun that
made this patina take better?

Jo Haemer
timothywgreen.com

10 
Elaine- Was it the UVs from the sun or the heat from the sun that
made this patina take better?

An excellent question. I don’t know. I did put them in a clear
Ziplock bag, so they did get both light and heat.

Elaine
CreativeTextureTools.com