Finishing metal clay jewelry starts where
firing ends. What you will need to
your studio depends on whether you
finish by hand, by machine, or both.
jewelry artists employ a mix of power
hand techniques because there are times
use one over another for the particular
being polished, to get a certain finish,
or to save time and work.
The general approach to finishing is to remove
any scratches or imperfections with files
and abrasives, then pre-polish, apply a patina
and then final polish.
There is nothing like the power of an electric
motor when it comes to finishing metal clay
jewelry. Whatever finish you are after, with
power tools you will be able to achieve it
in a fraction of the time it takes to do
by hand, or you'll be able to do it without
lifting a finger.
These are machines that can polish jewelry
in one step. They work by agitating or tumbling
the metal with stainless steel polishing
"shot" in a barrel or work bowl.
The action of the shot hitting the metal
surface thousands of times during the finishing
process results in a very shiny surface.
The shot is a mix of specially shaped pieces
designed to get into the nooks and crannies,
but it can't get into every tight spot, so
pieces are usually burnished with a brass
brush before tumbling.
Rotary Tumbler: a barrel containing the shot, burnishing
fluid and the jewelry pieces rotate for an
hour or more. The time needed to polish metals
depends on the kind of metal being tumbled.
Soft metals, such as fine silver, polish
in 1 to 2 hours. Harder metals, such as bronze,
need at least 2 hours, and 4 or more hours
is not uncommon. Rotary tumblers are fairly
quiet while running.
Vibratory Tumbler: these types of tumblers work about 50%
faster than rotary tumblers. They work by
vibration rather than tumbling. The drawback
is that they can be quite a bit louder than
Magnetic Tumbler: stainless steel pins are whirred about
with water and the jewelry pieces in a blender-like
machine. This type of tumbler works faster
than any other type. The drawback is that
it's very aggressive. Fine silver becomes
pitted very quickly. Use for harder metals
such as silver alloy and bronze clays.
Metal Brush: use to "burnish" fired metal
clay before tumbling. A fine brass brush
is used for silver and gold, steel is used
with bronze, brass and other metals. The
fine bristles give a soft matte finish.
Flexible Shaft Tool
This consists of a motor that turns a long flexible
shaft. At the end of the shaft is a handpiece
that holds miniature tools and drills. The
motor can be a "pendant" style
that is suspended on a "motor hanger"
that mounts or clamps to a table, or it can
be a "bench motor". A bench motor
is fixed to a base instead of hung. A foot
pedal controls the motor. The advantage of
a pendant-style motor is that it is off the
work surface so the shaft does not interfere
with tools on the bench.
Some flexible shafts work in both forward
and reverse directions, making them adaptable
to both left and right hand users, and for
times when reverse is needed.
When we talk about flexible shaft tools,
we are referring to professional grade
designed for jewelry work. A strong
and the ability to rotate at variable
is important. A 1/6 horsepower motor
standard for professional jewelry studios
worldwide. A less powerful motor limits
can be done.
Flexible Shaft Handpiece Options
There are 2 basic types of handpieces that
are useful in finishing work: chuck-style
and quick-change type. Some brands offer
only a chuck-style and others have "swappable"
parts so either type of handpiece can be
changed on the fly.
Quick Change Handpiece: offers the ability to flip a lever or pull
on the handpiece to release and change the
tool. This style can accepts shanks that
are 3/32" in diameter only. That may
sound limiting, but most professional jewelry
drills and accessories come standard with
a 3/32" shank.
Chuck-Style Handpiece: comes with a chuck-key that is used to
crank open the chuck to change the
The advantage of a chuck-style handpiece
is that it can accept any sized tool,
or drill shank from 0" up to 5/32".
The disadvantage is that it takes
open and close the chuck. Since tools
frequently changed, this can add up
lot of lost time and strain on the
The key used to open the chuck is easy
misplace, so attach the key to a chain
string and dangle it within easy reach.
Foot Pedal Options
most flexible shaft machines are operated
by foot pedal. Many brands offer a high-impact
plastic foot pedal standard in their kits.
A cast iron foot pedal, however offers additional
Plastic Foot Pedal: low cost and low weight. Does not typically
offer the sensitivity available in a cast
Cast Iron Foot Pedal: a small extra cost will give big returns
in control and comfort. A cast iron pedal
is heavy, so it stays where it's put. The
pedal action is more precise and glides more
smoothly, allowing for sensitive control.
Flexible Shaft Accessories:
the wide world of polishing and finishing
accessories offers many options for a variety
of finishes. These are some of the most useful
in a metal clay jewelry making studio.
Sanding Discs: are abrasives that can quickly remove material.
Used to smooth a surface, sand out scratches,
and to perfect an edge or shape.
Miniature Split Mandrels: a strip of sandpaper is inserted in the
split and wrapped around the mandrel, making
an effective tool for removing material,
such as when smoothing the inside of a ring
3M Bristle Discs: these can get into places that other tools
cannot. The bristles sweep into deep crevices
quickly and easily to give an all-over finish,
progressing from coarse grits to finer and
finer grits until the desired polish is achieved.
Satin Buffs & Mini Fiber Wheels: a beautiful satin finish can be applied
to metal in a matter of seconds with a mini
fiber wheel or satin buff. These are available
in various "grits" for different
types of finishes.
Silicone Polishing Points: these types of polishers are available
in special shapes and grits. The variety
of shapes are designed to get into various
nooks and crannies. For instance, a barrel
shape is used for the inside of a ring, and
a floppy disc shape is used for a flat surface.
Mounted Brushes: available with metal bristles such as steel
and brass for scratch finishes and burnishing,
and in natural and synthetic bristles for
Mounted Buffs: used to buff or "shine" pieces
as a final step. Muslin and felt wheels can
be used with or without polishing compound.
Hand finishing offers jewelry artists
personal connection to their work.
are simple, compact, portable, and
nothing more than elbow grease to operate.
Following correct polishing steps will
the desired finish very quickly. Like
finishing, you can opt for a simple
finish or for something more involved.
Burnishing is the process of rubbing a highly polished
steel tool over the metal to compact the
Metal clay has a "pickled" appearance
after firing. When examined under magnification,
the surface appears frosted. The frosted
surface is metal and does not need to be
removed, but burnished down. This burnishing
polishes the metal surface.
Metal Brush: also called a "scratch brush".
These are brushes with fine metal bristles
fixed in a handle or block. Brushing lightly
burnishes metal. Always use a brush with
bristles that are a harder metal than what
you are burnishing. Brass brushes are used
for silver and gold, and steel is used with
brass and bronze.
A matte finish is as easy as burnishing with
a metal brush. To accent the detail and give
a vintage look, next oxidize the surface
and then brush lightly to reveal the level
of soft matte finish desired.
Curved Burnisher: many metal clay artists are taught to use
nothing more than a curved burnisher and
a polishing cloth to polish metal clay. This
is an effective and low cost approach, but
takes more time. It is not possible to get
into tight areas with a curved burnisher,
so the addition of a scratch brush (a metal
brush, described above) will take care of
Ball Burnishers: are hand-held tools have steel balls at
the tip that are used to burnish in tight
spots and small places that a brush and curved
burnisher cannot reach. The pins are whirred
about with water and the jewelry pieces.
This type tumbler works even faster than
a vibratory tumbler, but is too aggressive
for soft metals like fine silver, but excellent
with harder metals such as bronze.
These are sheets and pads that have grit
adhered or embedded in the surface. An abrasive
is something that removes material, unlike
burnishers that only rub the material.
Sandpapers: wet/dry sandpapers in 220 and 400 grit
are the most useful in a metal clay jewelry
studio. These are one of the few metal clay
abrasives that can be purchased from a hardware
store. They are used as flat sheets or wrapped
around a wooden shape to customize a sanding
Sanding Pads: similar to sandpaper, but the sandpaper
is glued to a foam pad that is easy and comfortable
to use and offers polishing grits designed
The most aggressive of all finishing tools,
a file can remove a lot of material very
quickly. Files are available with different
"cuts", which refers to the cutting
Hand Files: a good hand file is essential to have in
the studio. A good flat file in a fine (cut
4) swiss pattern will help with squaring
up a flat edge very quickly.
Half Round Ring File: important tool for those making rings.
Get a nice one with a cut-4 swiss pattern.
Used to quickly smooth and refine the inside
of a ring shank.
Needle Files: a set of fine (swiss pattern, cut-4) is
used to remove scratches, refine and file
metal of all kinds. Dip the grip of these
files in tool coating for extra grip..
Diamond Needle Files: these are smaller than traditional needle
files. Diamonds cut through all metals
You'll want to dip the grip end of
of file in a tool coating for extra
: these are like paper towels with polishing
grit embedded in them. They are used, from
the coarsest 400 grit sheet through to the
8000 grit sheet to end up with a mirror shine.
: these are small pads that give a soft shine
in one stroke to fine silver and remove
: used as a final step to buff polished metal.
Polishing cloths are sometimes charged
tarnish inhibitors so the item you
with it stays shiny longer.