Transform virtually any metal surface from a dull rough finish to
a lustrous shine! The key to that satisfying gleam is knowing where
to start and understanding the difference between polishing and
buffing. Often novices use the terms 
interchangeably.
Polishing removes a heavy amount of material, like during sanding
or grinding. Buffing is the process that brings out the actual full
brilliance of a part. Parts with dented or scratched surfaces will
first require some conditioning before buffing can be effective.
Here we will discuss how to prepare parts for buffing.
Difficult to replace stainless steel trim is a perfect example
since it is almost never in a ready-to-buff state. Scratches and
dings may be removed in a similar manner to dents on a car body,
only on a smaller scale. Use a Mini Anvil
and Trim Hammer to 
raise
the dent. Blows of the hammer spiral in toward the center to minimize
stretching. Once the surface is relatively straight there are five
methods to make the part smooth enough for buffing. The most time
consuming is to block sand or file the part by hand, allowing for
the greatest control. Eastwood's Expander
Wheel (13079)
used at up to 2400 rpm with premium grade 3-M Trizact
Abrasive Bands will also level the surface and maintain the flatness
of the surface without rounding edges. This band serves the same
purpose as our regular abrasive bands except it's available in finer
grits and cuts more consistently throughout its longer life. Trizact
Bands can be used to get relatively flat surfaces smoother quicker
than any other abrasive, reducing buffing time. Scotch-Brite
Bands are also for use on the expander wheel, but due to their mesh-like
construction work better on slightly contoured surfaces. Edge marks
on the part are virtually eliminated due to the softer construction
of these bands. For smoothing highly contoured surfaces, Eastwood's
Greaseless
Compound
(13129,
31,
32,
94)
is the most effective. These compounds are applied to either Spiral
Sewn or Loose buffing wheels. Available in 80, 120, 220, and 320
grit, they convert your buff into a flexible grinding wheel. Tight
access areas can be polished and smoothed with 
Eastwood's
Abrasive Rolls (available in cylinder and tapered formats from 80
through 320 grit) and can be used on tapered mandrels ranging in
length from 2 ¾" - 6". Use the shortest
mandrel possible since excessive side loading will more easily bend
the longer mandrels. Felt bobs used with greaseless compounds mentioned
above act as another alternative to using abrasive rolls.
The Vibratory Tumbler Systems
Eastwood's vibratory
tumbler systems can be used for polishing and buffing small
parts, and are an effective alternative to hand finishing. The vibratory
type of tumbler works up to 25 times faster than rotating tumblers.
Actual process time will vary from a few hours to a few days, depending
on the condition of the parts and the finish desired. Parts to be
tumbled should be free of grease, oil residues and paint coatings.
The tumbler load should consist of 30% parts to 70% media, without
exceeding the maximum rated tumbler load of approx. 3 lbs. for the
small tumbler and 6 lbs. for the large tumbler. The pyramid shaped
Green
Rust Cutting Media is used both in the smaller bowl for the
small tumbler or the single heavy-duty bowl included with the larger
tumbler. Add enough water to just cover the media without creating
standing pools of water. It usually takes between 5-12 hours to
de-rust and clean moderately rusty parts. If a high shine is desired,
the parts can then be placed in the bowl with the Dry
Shine. This media will impart a high luster in 24 hours to a
few days.
Which Buffing Motor is Right for You?
When selecting a buffing
motor a number of factors need to be considered. If the buffer
is predominantly for buffing metal, choose 3600 RPM; if you'll be
predominantly buffing plastic, 1800 RPM is preferred. More powerful
motors yield faster results because larger diameter wheels and/or
multiple wheels can be used on the same shaft. The lower power motors
will get the job done but will take more time. For buffing light
pieces of stainless steel trim, many prefer a smaller buffing wheel,
which can be used on the small buffing motors or modified by making
a small cut north, south, east and west around the arbor hole to
fit the larger buff motors.
All of the buff motors we sell feature sealed cases and long shafts
supported by ball bearings. The Eastwood Buffing
Motors represent remarkable value and performance that will
nicely suit most hobbyist and professional needs. The Baldor Motors
have long been the industry standard for excellence and offer slightly
longer shafts for improved maneuverability.
Mandrels and Adapters - Using an Existing Motor For Buffing
If you prefer to use an existing motor for polishing and buffing
operations, Eastwood 
sells
a wide variety of Motor
Adapters to fit motor shafts from 3/8" to ¾".
The 1/2" and larger mandrels are available in right- and left-hand
thread. To determine which thread you need, examine the unit to
see if the shaft is to the right or the left of the motor. If your
shaft is to the right, use a RH adapter, and a LH adapter if the
shaft is to the left of the motor. The Wheel Arbor (13064)
is used to mount our smaller wheels with ½" mounting
holes to your drill or die grinder. If using this adapter with a
drill, be sure the drill spins at least 2500rpm -- low rpm is the
leading cause for difficulty in transferring compound the wheel.
For our Mini
Buffs (1-2" diameter) we have 2 mandrels - ¼"
(13054)
1/8" shank (13063).
These 2 sizes allow the buffs to be used with most die grinders.
Getting Ready to Buff
Once the surface is smooth enough to buff (i.e., 220 grit or finer
for soft metals like aluminum, brass, copper, and pewter; 400 grit
or finer for steel and stainless) the buffing process can begin.
As mentioned earlier in the polishing/preparation section, Trizact
Bands can be used to substantially speed up the buffing process.
When using the A-30 (700 grit) and A-16 (12000 grit) bands on aluminum
or other soft metals, use either Eastwood Tripoli
compound or Eastwood Grinder's
Grease on the Trizact band. Running these fine belts dry can
pull grains of metal from the part and drag them across the surface
resulting in a rough finish. Using the Trizact bands saves substantial
time and eliminate one or 2 buffing steps.
Buffing Safely
Buffers spin at a high RPM (usually 3600 rpm), which is more than
enough to launch parts across the room or into you if the part is
not held properly. Make contact with the lower (4:00 position when
viewed from the left) portion of the wheel. The wheel should pass
over corners and edges, not toward corners and edges. Hold the piece
tightly and apply light (about 2 lb.) pressure against the wheel.
Do not insert your hand or fingers into openings. Practice how you
will hold the piece against the wheel before starting the motor.
Once you're satisfied you can hold the part safely, you're ready
to put on your gloves, dust mask and eye protection and begin buffing.
To
apply the compound to the wheel, tear down the cardboard tube and
hold the exposed compound against the wheel for about 2 seconds.
You'll see how the wheel takes on the color of the compound. You'll
also notice how the wheel turns black almost immediately when you
start to buff. This black build-up is not harmful to the wheel or
the part being buffed. Rake
the wheel if you notice excessive metallic build-up or at the start
of the day to prevent scratching the surface.
As you progress from one compound to the next finer grit remember
to clean any residue with Eastwood PRE
Painting Prep (10041Z),
Metal
Wash (10120),
or hot water and detergent and change the angle by 90 degrees (or
as close to 90 as the configuration of the part allows). Before
you stop to inspect your work, take a few passes with the direction
of rotation. This technique will help remove fine scratches for
a better shine. In the finishing industry a "black finish"
represents the highest reflectivity. If the buffed surface can reflect
black without showing any fine scratches, then the best finish has
been achieved.
Preserving The Shine
Buffed surfaces will stay oxide free longer than rough metal,
but in many cases the durability of the shine can be enhanced with
the use of clear coats. Stainless steel, gold, and platinum do not
need to be top coated with a clear, but brass, copper, aluminum,
silver, pewter and most other metals will benefit from a clear coat.
The most durable clear to use is Eastwood's Super
Gloss Clear (10286)
HotCoat powder. Some types of brass, bronze and steel can significantly
oxidize when exposed to the curing temperature, in which case Eastwood's
Diamond Clear Gloss for Bare Metal (10200Z
in Aerosol form) and (10189Z
in pint form) can be easily applied after degreasing for durable
oxidation prevention.
