Foredom Polishing - Manual

Buffing and Polishing continued
C. Keep the workpiece in constant
motion, turning it quickly. This will help
avoid buffing or scratch marks. As a rule
of thumb, 80%–90% of the operation
will be spent on buffing (usually with
Tripoli), and 10%–20% will be spent on
the final polishing operation usually
with platinum white or red rouge.
6. Cleaning
Always clean the residue of a compound
off the workpiece before switching to
another compound. Generally, a hot
water solution with a few drops of
ammonia works well. An ultrasonic
cleaner can also speed up the cleaning
operation. Dry thoroughly.
7. Terms and Definitions
Burnishing – A metal surface is bright-
ened with a highly polished tool. Often
used to remove deep scratches or to
add contour, such as a beveled edge.
Buffing (Coarse) – “Cutting down”
with a coarse compound, such as Emery,
to remove surface blemishes. A thin
layer of metal (scratch deep) is actually
removed. Requires surface speed.
Prepares surface for polishing.
Coloring – Bringing out the natural
color and luster of precious metals.
Usually accomplished with softer or
finer compounds (ie. Platinum White or
Red Rouge).
Compound – The material applied to
the wheel or bob for the desired
finished effect – ranging from coarse
Emery cake with grit, to ultra-smooth
rouges with no grit.
Cutting Down – The initial stage of
buffing, using an abrasive compound to
remove a layer of metal (scratch deep).
Polishing – Adds color and luster to
the final stage of finishing. Usually
accomplished with the smoother
compounds. Requires a slower wheel
speed than buffing.
Surface Speed – The surface speed
per minute (SFPM) is the speed of the
buffing wheel as it revolves. The size of
the wheel has a direct relationship to the
surface speed.
Formula for calculating SFPM:
SFPM = 1/4 of the diameter of the wheel
(in inches) x RPM of motor
For example: A Foredom BL Bench
Lathe with a 4
″ diameter muslin wheel
at the maximum speed of 7,000 RPM.
1/4 of the diameter of the wheel = 1 inch.
1 inch x 7,000 RPM = 7,000 SFPM (Ideal
for buffing.)
8. Choosing the right wheel or
bob for your needs
Buffs vary in size, hardness, material
composition, and shape. Selecting the
appropriate one for each buffing or
polishing operation may require some
experimentation. Solid felt buffs and bobs
can be used for all types of buffing and
polishing operations with gritty or smooth
compounds. They come in various shapes
and hardnesses from medium to rock
hard. Small shapes, such as cones, balls,
square edge wheels or knife edge wheels
are used for hard-to-reach areas inside
grooves or rings.
Loosely-stitched soft cotton buffs are for
delicate work on precious metals, and for
polishing. Closely-stitched hard or stiff
cotton wheels and rock hard felt buffs are
used for cutting down and coarse buffing
operations on hard metals. Foredom’s
complete selection of 4
″ and smaller
diameter buffs and compounds is shown
in this guide.
After selecting the buff and compound
that seems appropriate for the work, it is
a good idea to experiment on a piece of
scrap metal to determine what finish will
result at various speeds.
FOREDOM ®
Buffing and Polishing Guide
1. Safety Recommendations
Always wear safety glasses to prevent
eye injury caused by flying debris or
injury from a piece that is thrown back
by the wheel.
Do not wear loose clothing which might
get caught in the equipment.
Always wear a respirator and work in a
well-ventilated area to avoid inhaling
dust into your lungs. Foredom’s new
Filter Hood helps remove hazardous
dust – see listing inside.
Always hold your work firmly. Gloves
are a practical way to hold items that
become hot. Small pieces should be held
with a hand vise or wedge clamp.
2. Applying Foredom compounds
to buffing wheels on lathes
A. While the wheel is revolving toward
you, pass a bar of compound lightly
across the face of the wheel, slightly
below the motor spindle (See Fig. 1),
until the face of the wheel is lightly
coated. Always apply the compound to
the wheel and never to the article itself.
B. Spread the compound evenly by
holding a clean piece of flat metal
against the wheel face. When the
compound is evenly distributed, the
wheel is ready for buffing or polishing.
Apply additional compound as needed
with a wiping motion.
Fig. 1
Compound
C. Experiment with different compounds
on scrap pieces to determine which com-
pound gives the desired effect.
3. Applying Foredom compound
to buffs mounted on mandrels
(flex shaft handpieces)
A. Pass the bob or wheel lightly over
the bar of compound. Be careful not
to overload.
B. Spread the compound over the
surface of the bob or wheel by lightly
rubbing it on a piece of clean, flat metal,
until the compound is evenly distributed.
C. Reapply in the same manner,
when needed.
4. Applying compounds
to previously used wheels
It is best to use a separate wheel for
each type of compound to avoid contam-
ination and scratches. When absolutely
necessary, used wheels should be cleaned
by holding a file edge or the edge of a
hack saw blade against the revolving
wheel. Only coarser compounds than
the one used previously should be
applied to the used wheel. Never use a
final polishing or coloring compound on
a wheel or buff that has been previously
used for coarse cutting or buffing.
5. Buffing and Polishing
A. Make sure the wheel is revolving
toward you from top to bottom. Grasp
your workpiece firmly, remembering that
metal will become hot during buffing or
polishing operations. Small articles can
be held with hand vises or wedge
clamps, and chains can be wrapped
around a piece of wood. Keep the upper
edge of the workpiece away from the
wheel to avoid having it torn from
your hands.
B. Press the workpiece firmly against the
revolving wheel, slightly below the
center. (The compound will stick to the
article if you are pressing too lightly; and
the wheel will slow down if you are
pressing too firmly. See Fig. 2.)
Fig. 2
Surface to
be polished
Buffs 3 ″ and larger are for use on
tapered spindles at 5,000 RPM
Max Speed.
Use 1
″ and 2″ buffs with an A-M78
mandrel at 20,000 RPM Max Speed.