Aluminum Polishing Part VI - Polishing
Posted by Jay Schneider. Filed under Aviation.
June 8, 2011
Definition: A usual second step to compounding. Removing defects previously left by the compounding stage.
The start of the polishing stage is determined by the end of the compounding stage. Once the operator is satisfied with the finish laid down by compounding, it is time to start bringing up the shine by removing the marks left behind from the compounding stage. There are several ways to accomplish this.
One common way to polish an aluminum surface is to use the existing polish, but change the buffing pad fiber length. Say for example you are using the same polish you used for the compounding stage. Simply change the aggression of the pad to a lesser aggressive one and start there. For a faster cutting action, I prefer 100%, 4 ply twisted wool with about a 1” pile height. To polish that same surface using the same polish, simply swap out the pads pile height from a 1” pile height to a 1 ½” pile height, - you have now changed the level of aggression by moving to a longer pile height. To get my point across on how this works, picture a split bristle scrub brush with 3” bristles. Now shorten the bristles to about ½” in length. You now have a finger nail scrub brush – by keeping the strand material the same and shortening it, we have changed the
way the same bristle works.
Another way to change the aggression of the pad is to change the type of fiber that makes up the pad content. Wool fibers are generally more aggressive than acrylic fibers. A pad with wool fibers blended with acrylic fibers will be less aggressive than a 100% wool pad, and will perform well as an excellent polishing pad creating less surface friction, (which equals less heat), and fewer swirls.
During the polishing process, it becomes more important to keep the surface of the pad from loading up with excessive compound. Excessive compound will create heat and swirls – a big “No No” when polishing aluminum. Target fewer polishing machine RPM’s - somewhere around 1200 to 1500 RPM’s should be sufficient. Work an area of about 1 to 2 surface square feet in optimum temperatures of about 65 to 80 degrees. It is also advisable to use less surface pressure on the machine as well.
Aluminum polishing is probably the hardest, (and most frustrating!), substrate to perfect. It is of an art form. But with a lot of patience and perseverance, it can be perfected and very rewarding.
Next up? Final Finishing
Keep the Blue Skies Up and Happy Motoring!
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