Metal polishing require a specific sequence of wheels and compounds to achieve a smooth and bright metal surface. If you follow an incorrect sequence for metal polishing, it can leave scratch and haze on the metal surfaces. A color chart is use to determine the correct wheel and compound to use on a specific metal.
The color chart display the sequence of compounds in which to use wheels to avoid guessing which wheel to use on the metal. The color chart also demonstrates that different color of polishing wheels serve specific purposes. Black wheels are stiff and used for removing rust and mill scale from steels.
Metal Polishing Steps and Wheel Color Guide
Sisal wheels are also used for removing rust and scale because sisal is a natural fiber. After use black or sisal wheels, you must use a softer wheel. Yellow treated muslin wheels are softer and will leave a brighter color on the metal.
This color provide the foundation for the metal to be polished. White flannel and blue airway wheels are used for the refinement of metal. These two type of wheels are soft and hold fine rouge without the rouge getting clogged in the wheel.
Blue airway wheels have an open construction that allows heat to dissipate during the polishing processes. You must use the color chart sequence because using softer wheels after using a stiff wheel will prevent leaving scratches on the metal. If you skip any step in the process, you will have to repeat the process to achieve a bright finish on the metal because of haze or swirl marks will be left on the metal surface.
Certain compounds of metal polishing solutions is used for specific metals. Brown tripoli compound is used on aluminum, brass, and copper metals because it cut quickly on these metals but does not leave deep lines in the metal. White and red rouge compounds are used after the metal is smooth.
Using the correct compound for the metal is required because using the wrong compound can cause further damage to the metal. For instance, using brown tripoli on stainless steel will make the metal smear on the metal’s surface. Green chromium compound is used on stainless steel to break through the oxide layer on the metal without discoloring it.
The construction of metal wheels determine the types of metals with which they are used. Sewn wheels are firm because of the stitching on the wheel. These metals are used on flat metal parts because the firmness of the wheel allow for enough pressure to be used on the flat metal.
Loose wheels are not sewn and are not firm in there construction. Loose wheels are used on metal parts with curves so that the wheel can conform to those curves. Sewn wheels are used on flat metal parts while loose wheels are used on metal parts with curves.
The metal to be polished will determine the entire metal polishing sequence. Carbon steel metals are very tough and can take the abuse of abrasive metals and compounds. Aluminum metals requires a lighter touch with the polishing wheels because aluminum metals can warp under high heat.
Chrome plating metals are very delicate. The metal will have to be polished with white rouge on a soft wheel. Any pressing too hard on chrome plating will result in the chrome plating dissapearing from the metal.
Metals such as gold and silver will also require fine rouge and low RPM for the polishing wheels to avoid damaging the metal’s surface. The size of the metal polishing wheel and the speed with which it will polish the metal are also important considerations in the metal polishing process. A larger metal polishing wheel will have more surface speed at the same RPM of the motor.
The wheel will have a specific RPM it can handle. For example, a metal polishing wheel rated at 7,500 RPM will fail if used with a metal grinding tool that has a higher RPM. The rating of the polishing wheel must be checked before mounting the polishing wheel to the metal grinder and with the metal grinder that will be use to polish the metal parts.
The use of a color chart shows a three-step sequence of metal polishing that can be used repeatedly to polish metals. The first step is to cut the metal to remove any defect in the metal parts. The second step is to use different colors of polishing powder to build brightness on the metal parts.
The third and last step is to use a final buff on the metal parts to polish them to a mirror finish. Each stage of metal polishing with different wheels and compounds will prevent the compounds from getting cross contaminated with each other. If followed correctly, the polished metal parts will reflect a clear image without any haze or lines left on their surfaces.
