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Pickling brass

Does anyone know a trick for getting the firescale off brass after
soldering. Is there any solution I should be using other than Sparex
for after solder cleaning. Rachelle

Hydrogen Peroxide pickle ratio:

2/3 cup hydrogen peroxide
1/3 cup water
1 tbl spoon dry pickle

I’ve found it is best to use this only for those areas that you
can’t get to manually to avoid over-pickling. The solution works
best hot and it gives off nasty fumes so be sure to work in a
ventilated area. It shouldn’t take long to take off the pink
(firesacle areas will bubble like alka seltzer) and overpickling can
give the surface an etched texture or discolor the metal so stick by
it and check it often. The solution only stays potent for a couple
of hours and must be disposed of carefully, like standard pickle.

-jo nelson

   Does anyone know a trick for getting the firescale off brass
after soldering. Is there any solution I should be using other than
Sparex for after solder cleaning. Rachelle 

I have found that dipping it in a solution of nitric acid and water
works just fine. Just a short dip is sufficient as you don’t want to
etch to surface of the brass. Alma

   Does anyone know a trick for getting the firescale off brass
after soldering. Is there any solution I should be using other than
Sparex for after solder cleaning. Rachelle 

Take a scoop full of your sparex pickle. Mix it with an equal amount
of hydrogen peroxide from the drug store (fairly dilute). This strips
off the copper flashing in about 2 minutes. The peroxide turns back
into water with time. Charles

Charles Lewton-Brain
Box 1624, Ste M, Calgary, Alberta, T2P 2L7, Canada

G’day Rachelle. For removing the Firescale after Casting, Annealing
and Soldering Brass and Bronze I Pickle the item in Sparex and then
use a Bright Dip made up of 50% Nitric Acid and 50% Water. The item
after pickling in the Sparex is first washed in clean water then
dipped in the Bright Dip for a few seconds and removed then into
clean water, the item is then examined to check that all the scale
is removed, If clean the item is then placed in a solution of fresh
clean water and Sodium Bicarbonate (I use about 2 Table spoons per
Litre of Water) to Neutralise any traces of the Nitric Acid. If
there is still some Firescale the Item is then re-dipped until
clean. Word of Caution with the Bright Dip, Use in a well
ventilated area, Rubber Gloves and Eye Protection and plenty of the
Neutralising solution standing by for spills, and Avoid the Toxic
Brown Fumes given off.

Please Read through the Orchid Archives as there is a lot of
there about this subject.

Best Wishes.
Michael W Kohlleppel. (Metallurgist)
Art Tech Castings Australia.

Rachelle - its pretty easy to get rid of the pink stuff. Just add
25% hydrogen peroxide - drugstore variety - to your pickle. Cold
pickle works fine in this case. As usual there is a catch - if you
let it go too long, the brass will pit. So watch. Also works on

Judy Hoch, G.G.

Do you really have firescale or is it a pinkish coating?

Marilyn Smith

The best and quickest way to pickle brass (after using Sparex, which
only gets rid of the black [but not the red] copper oxide and the
flux glaze) is to use diluted (50:50) nitric acid. I have used it
for 20 years without incident, but you must treat it with respect,
since it’s a strong acid. Failing that, you can try the mixture of
Sparex and hydrogen peroxide, described in a paper costing 75=A2 from
Reactive Metals, Inc. It takes longer to work. HTH. Judy Bjorkman

The peroxide Pickle mix works well to get rid of copper flashing on
silver that has been pickled in contact with iron as well.

Tony Konrath
Gold and Stone

Hello: One small item to add: if it is just the copper flashing you
want to remove from the brass, there is no need to do that before
secondary soldering steps. The copper coating will not hinder
soldering. When all soldering is complete, then remove the copper,
as stated earlier, with the hydrogen peroxide pickle. If the
firescale to which you are referring is black or brown, then that’s
another story. You can’t solder over that. That may just take longer
to remove in the original pickling. If it remains, you may have to
remove it manually from the area of the next solder joint before

A tip for using the hydrogen peroxide pickle: watch your pieces
carefully as they pickle. The second the copper is gone, pick up the
piece with a plastic tweezers and drop it quickly into a container
of water. (Plastic tweezers rather than copper to avoid saturating
the solution too quickly) Exposure to much air before rinsing turns
it black. Then rinse repeatedly. Neutralize with baking soda and
water, as stated before. The surface may still be slightly etched. A
run in the tumbler will take care of that; it’s easy to polish out
too. If you have a number of pieces to do, it’s much easier to batch
them for these processes. Good luck! Lin Lahlum

Another good recipe for removing copper from brass:

1/3 c. citric acid
1/3 c. hydrogen peroxide
1 c. water

Heat the water until boiling, add the citric acid and hydrogen

It fuzzes off brass in a snap! Rinse well.

–karen christians

Karen, Can you please tell me about using ALUM as a pickling solution
dissolved in water? If you received a similar message, sorry for the

Dave Hall, Gainesville, FL