Speckled patina on brass

Hi everyone,

I was fooling around with Jax brown/black brass darkener – selenious
acid is its main ingredient – and ended up with tiny yellow speckles
on part of the brass. It was before I cleaned the metal, but I cannot
reproduce it. Does anyone have any idea? I know it’s not supposed to
do that, but I thought it was beautiful!

Thanks in advance,
Abigail

I cannot reproduce it. Does anyone have any idea? 

Sprinkle the wet patina on the bass with fine salt?

Noel

Noel,

There are many ways to achieve the speckled or mottled patinas. One
way is to use sawdust (think coarse, medium or fine) which has been
dampened with the appropriate solution (not soaked). The sawdust is
placed along with the piece in a sealed container (Zip lock will
work) and NOT MOVED for a few minutes or hours or overnight.
Experimentation is in order, room temperature plays a part.

Some creative thinking about the materials which come in contact with
your metal piece can lead down lots of fun roads, not all explored
thoroughly.

Have fun!
Wayne Emery

There are many ways to achieve the speckled or mottled patinas.
One way is to use sawdust (think coarse, medium or fine) which has
been dampened with the appropriate solution (not soaked). 

Also hot patinas can be spritzed on from a distance to the spray
particles/droplets can spread out and form a random pattern. Or a
tooth brush wetted with the patina solution and via bristle brushing
with the tip of one’s finger, the drops are released, or via a short
haired paint brush, same technique as the tooth brush. Mottled
patinas can be done with hot patinas by dabbing with a brush (tips
only) or a piece of sea sponge. Piece has to be hot enough to keep
the liquid patina solution from running (also application item must
be “dry” enough. If you want a “ring” of patina and little or no
color in the center of the mottling, use very dilute patina
solutions and hold the brush/sponge in place on the piece for a few
seconds. If you want the whole sponge/brush area to be colored use
more concentrated solutions and do not hold the sponge/brush on the
surface very long (more like just a dab). Piece of rag, piece of
crumpled paper leaves, grass, etc. can all be used for applicators.
Also crushed stone, smooth stone, seeds, plain dirt and most
anything with a “grain” can be used in the “sawdust” method given
above.

There is much more technique/on patination than given
here. This is to get you started.

John Dach

Thanks so much to everyone for your patina suggestions. I’m trying
all of them. But I’m still curious about the very first effect that I
got, just dipping a piece of (uncleaned) brass into the selenic acid
solution. It came out very dark with quite wonderful teeny tiny
bright yellow dots. Brighter and yellower than the brass.

Abigail

If you could duplicate the contamination on the metal you could
probably repeat the dot patina.

JD

Yes, John, you were right. Looks like the speckles were from
something – iron, I’m guessing – in my well-water.

Thanks!
Abigail