Getting Ready to Buff - Surface conditioning and smoothing

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 </coupon.jsp?keyword=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. Non Woven abrasive </coupon.jsp?keyword=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 our 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. Used on tapered mandrels ranging in length from 2 ¾" - 6". Use the shortestmandrel 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 we sell can be used for polishing and buffing small parts, and is 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 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 </coupon.jsp?keyword=Buffing+Motor> 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 or more. Low rpm is the leading cause for difficulty in transferring compound to 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 eliminates 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 (10200Zin Aerosol form) and (10189Z in quart form) can be easily applied after degreasing for durable oxidation prevention.