Polishing and buffing seems to be the one area that is misunderstood the most. Preparation is the most important part of plating, without it it is impossible to do a good job. In plating, preparation is everything. The work piece must be polished and cleaned prior to plating, without these steps you will be disappointed in the job you are doing. If the piece is not clean, more than likely the plating won't even stick or be spotty at best.
It is important that you understand that whatever the finish looks like before the final plate, is exactly what it will look like after you apply the chrome or gold. The polish or shine that is on the work piece and especially on the nickel before applying the final plate determine what the final results will be. In other words if you have a piece that is polished but you left a scratch or pit in it, when you apply the chrome or gold you will have a piece that is shinny but with a scratch or pit. If the piece has a brushed or satin finish before your final layer, then the results will be a piece with a brushed or satin finish. And that will apply no matter if you are tank or brush plating. The only acceptances to that rule is when you are finishing a piece with silver a plate. If the piece is plated in silver than you have to do a little hand polishing with a silver polish. Silver plates out with a white looking finish, it is what jewelers get after soldering silver jewelry and then putting it in a pickling solution to take off the fire scale. I have always used Wright's Silver Cream which can be purchased in grocery stores for my final polish over silver. It is a cream and comes with a sponge in the jar. All you have to do is apply the polish with the sponge that comes in the bottle, rinse it off and dry with a soft cloth.
I have had customers call me and say that they can't get a shine on their gold or chrome plating. When I asked one of them if they had polished the piece before plating they replied that they sure had. They rubbed it with a rag for 20 minutes. Another told me he had polished it with Simonize.
Generally when you have a piece that has deep pits or scratches you will start out with sandpaper. Sanding metal is no different then sanding on wood. You start with a course sandpaper and work your way down to a finer and finer grit until you achieve a smooth surface or polish. It is best to use sandpaper if you have a rough surface.
When sanding do not use your finger or hand under the sand paper. Doing this will make a low spot or flat spot on the piece. Always sand with a sanding block or piece of wood behind the sandpaper, and let your motion follow the curve of the work piece.
Bead blasting or sand blasting is another good method of preparing the piece if you have one available especially if there is old uneven plating or paint on the piece.
After you finish sanding the piece then you can buff the piece on a buffer to a high shine.
Red Rouge produces a very high luster or color on gold, silver plate, sterling and precious metals. This is the industry standard for producing the final polish.
White rouge is a quick cutter for all hard metals such as stainless steel, chrome, nickel, white gold, and cast brass. It should not be used on plated items, use previously to plating.
Fabulustre is a greaseless finishing compound for use on precious metals. It also works on plastics. Removes light scratches and will not discolor work.
Zam is a compound used for achieving a high finish on chromium, stainless steel, nickel and other metals. It leaves behind little residue, so clean up is fast.
Brown Tripoli is used to achieve a fast cutting action and some degree of color on gold, silver, brass, copper, aluminum, and other soft metals. Used to clean up minor scratches and light work. Use a medium spiral sewn buff. Tripoli is used for general cutting of non-ferrous metals ( aluminum, brass, copper, and zinc diecast. Use with a sewn buff.
Emery is used on hard metals like iron, and steel for removing scratches and rust. It is not for use on gold or silver.
Yellow Rouge is for hard metals such as stainless steel, brass, and particularly platinum. It is a good general purpose compound.
Use tightly sewn buffs with more aggressive compounds. Less aggressive compounds should be used with a softer (looser sewn buff).
All compounds can cut through plating. If you are not careful you can do more damage then good. Make sure that you use a polishing compound that is not aggressive. Use a very light pressure on the wheel working with a loose buff.
For polishing or cleaning an aluminum wheel first check the wheel for clear coat. This has to be removed by sanding or sand blasting before polishing. The polishing is a two step process. First use Tripoli and a buffing wheel to remove scratches. Second use jewelers rouge (red rouge) and a new buff, finish out the fine lines and blend. After you have the wheel polished out, use a good quality aluminum polish and hand polish the wheel. This will clean and add a protective layer on the wheel.