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Brass treatment to prevent tarnish


#1

hello,

I have begun incorporating brass into my sterling silver designs.
does anyone know if renaissance wax is a good coating for brass to
preserve the color and prevent tarnish?

also, should brass be kept out of the pickle? mine turned pink.

thanks!
susan


#2
Should brass be kept out of the pickle? mine turned pink. 

Well no, “pink” usually means iron or steel contamination (well it
did for us).

Regards Charles A.


#3

We have also had problems with pickle in which red brass has been
"pickled", turning silver pink.

Margaret


#4

Brass typically copper plates a bit in the pickle. I make up a
solution of half white vinegar & half hydrogen peroxide & let it sit
for a while. (Maybe half an hour? I’ve never timed it- I just drop
the stuff in & go work on other things then check when I finally
remember I’ve got something soaking.) The solution should be room
temperature. If you heat it up, it’ll etch the surface of the metal &
then quit working. Once it’s clean & yellow again, it’s done. :slight_smile:

I’ve got a pot of it in the metals studio at school. My Prof is
convinced it’s some sort of faerie magic I’ve worked out. :smiley:

I’ve used Renaissance Wax on brass, bronze & copper. It’ll help a
bit, if the piece isn’t being handled a lot.

Sharon,
Artist, Metalsmith, Chaos Magnet


#5

Renaissance wax protects brass from losing its shine, but you will
need to reapply it once in a while if it’s subject to a lot of
handling or exposure to chemicals in the air. To avoid pink brass,
put it in a solution of half pickle (warm) and half peroxide… The
pink will vanish and the brass will revert to its original color.

Dee


#6

It might be best for James to respond to this question as to why it
happens but…don’t worry about the ‘pink’ on your brass. Do the
same thing you do when a piece of silver is contaminated with
copper. Take a small cup of pickle, add hydrogen peroxide about
30-50% and soak the piece. Afterwards, brush with a brass brush with
some liquid soap. Cleans it up beautifully!!

Cheers from Don in SOFL


#7

Susan,

I saw your question on Ganoksin & I think I have a solution for you.
I’ve been using a lot of brass lately, due to the high cost of gold,
and I had the same problem.

After torching my brass piece, I place it in warm pickle first,
which brings copper to the surface (the pink coating you mentioned).
However, I then put it over into a mixture of warm pickle & hydrogen
peroxide for about 10 minutes (1-to-1 mixture, or 2 parts pickle to 1
part hydrogen peroxide- I’ve done it successfully both ways). The
result is a beautiful matte gold finish, which I love.

You might be able to skip the step of placing it in plain pickle
first - I’ve just always done it that way, but I’m going to skip that
step on my next piece to see if it still works as well. And I’ve been
told that the pickle/peroxide mixture doesn’t have to be warm
(although the warmth will supposedly speed up the process).

I keep a separate pickle pot that I use exclusively for this
purpose. From this special pot, I pull out however much warm pickle I
need, mix it with the peroxide in a plastic cup, & add my brass
piece. When I’m done with the mixture, I remove my brass piece & pour
the liquid mixture back into that same special pot with the original
pickle inside. Bear in mind that this process continually dilutes the
pickle with more & more peroxide. At some point, I’m sure this
mixture will be mostly peroxide & may no longer be as effective. I’ve
done this about 8 times so far and it still works very well with my
diluted solution, so I’m going to keep going with it until it quits
cleaning my brass, and then I’ll dump it, make a fresh pot, and
start over.

I hope this helps!
Sissy Watson


#8

I am curious about the peroxide pickle discussion - way back in
chemistry classes when I often window gazed at the T-Rex’s out the
window, I was told that hydrogen peroxide loses its peroxide nature
and becomes just water fairly quickly. Was my teacher (horror of
horrors) mistaken?

Questioningly
Barbara


#9

Renaissance Wax is apparently the “gold standard” for protecting
metals and many other substances in museums world-wide, but it’s a
bit expensive and I think there’s only 1 distributor in the U.S.I
have found an excellent substitute. Now don’t laugh at the name. It’s
"Butcher’s Bowling Alley Wax!" (The Butcher Co, Marlborough, MASS. )
It’s clear and non-yellowing, and like the high-priced spread is
mostly carnauba. It’s blurb says it’s been used in Boston’s finest
homes since 1880.I have used it on jewelry and ancient coins that
I’ve had for 15 years and it gets my vote.

Gary Strickland, GJG


#10

I always keep a separate pickle pot for brass and copper and never
let those metals into my pot for silver. And, as much of my early
lessons for by beginning silver class is taught using copper, that
copper/brass pickle pot get pretty blue after awhile with all the
copper ions that have beens stipped off of the pieces. Even with no
contamination with iron in the pot, it is not uncommon for brass
pieces to loose their traditional golden color and come out of the
picke with the pink copper patina on them.

One solution [both an answer and a chemical mixture! ]for 'pink"
brass is to use “super pickle”. Warm a mixture of 1 part vineger to
3 parts household hydrogen peroxide in a dish. (Warm, but not
boiling.) Soak the brass in the mixture for at least five minutes.
Pull out and rinse in water. The super pickle will loosten the
copper patina. Gently rub with a brass brush and soap and it should
come off, returning you brass to its original golden, yellow color.
It might take two trips into the super pickle if it’s especially
bad.

The hydrogen peroxide wears out after a few hours, so a fresh
solution should be used each time.

Thanks to Phil Baldwin for this “tip” originally.
Denny Turner


#11

It’s my understanding that the pink is caused by copper rising to
the surface after being heated. I easily got rid of it by soaking my
piece in a solution of 1/2 hot pickle + 1/2 peroxide. Beware of the
fumes - they’re nasty.

Sheila


#12
It's my understanding that the pink is caused by copper rising to
the surface after being heated. 

The copper doesn’t rise to the surface. It’s already there. Remember
that with brass, copper is the major componant of the alloy. The pink
comes, instead, when you remove the other compant, the zinc. Heating
easily oxides the zinc, which then is removed by the pickle. It’s
removal also leaves the surface very slightly porous and rougher,
with also accentuates the different looking color.

What the peroxide/pickle mix is doing is to “supercharge” the
pickle. Ordinarily, sodium bisulphate (an acid salt of sulphuric
acid) is mostly effective at removing oxides, and affects actual
metallic copper only quite slowly, much more slowly that actual
sulphuric acid would do. And if there’s much existing copper already
dissolved in the pickle, then attack of existing copper is even
slower (The copper gets into the pickle mostly from dissolving copper
oxide, but once in solution, the copper ions are available as copper
for any chemical or electrochemical reactions, such as those
responsible for plating copper out on your silver if there’s iron in
contact with the silver) What the peroxide does in the supercharged
pickle is to act as an additional oxidizer, which allows the pickle
to much more actively attack the copper, actually etching it away.
What is left then, is the original color, since by removing that
surface layer of copper that’s been depleted of zinc, you then
uncover the underlying metal that still has it’s zinc, so the color
is then back to what it should be.

Peter Rowe


#13
I was told that hydrogen peroxide loses its peroxide nature and
becomes just water fairly quickly. Was my teacher (horror of
horrors) mistaken? 

No. Peroxide/pickle mixes have a short shelf life before the
peroxide componant becomes just plain water again. That leaves
ordinary pickle, but a bit more dilute, and it will perform as plain
pickle again. When you need the peroxide/pickle mix, you have to mix
up a new batch. It will stay active for a number of hours, but not a
number of days. Your teacher was correct.

Peter


#14
I was told that hydrogen peroxide loses its peroxide nature and
becomes just water fairly quickly. Was my teacher (horror of
horrors) mistaken? 

Not at all.

M’lou


#15
It's my understanding that the pink is caused by copper rising to
the surface after being heated. 

Well really it is the zinc burning off (oxidizing) leaving a copper
rich surface behind but it makes little difference. Hydrogen
peroxide pickle takes care of it as you say.

James Binnion
James Binnion Metal Arts


#16
Renaissance Wax is apparently the "gold standard" for protecting
metals and many other substances in museums world-wide, but it's a
bit expensive and I think there's only 1 distributor in the U.S. 

There are a number of places to get Renaissance Wax in the US.

You can get it on Amazon:

Woodworkers use Renaissance Wax, you can buy it online from Highland
Hardware at:
http://www.ganoksin.com/gnkurl/1nr

You can also get it at Woodcraft. Woodcraft has about 75 stores
around the US, so you might find it in a city near you:

No association to any of those stores except that I send them my
money from time to time.

Whit


#17
It's my understanding that the pink is caused by copper rising to
the surface after being heated. 

The pink is more likely composed of cuprous oxide (Cu2O). Any black
material is cupric oxide (CuO), which comes off easily in the
pickle. Check the Orchid Archives – we’ve had lots of discussion on
this in the past.

Judy Bjorkman


#18

Brass needs a coating of some sort. Some 45 yrs ago I used a
cellulose clear laquer on some brass and copper items I made. Its
still as good as the day I put it on. it doesnt get handled tho!!.

It was brushed on.