A Guide to Choosing the Best Grinder for Metal Polishing

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Many customers often ask us about the best grinder for metal polishing. This choice largely depends on your skill level, but certain machines can significantly impact how your aluminum and stainless steel pieces look, turning them into a mirror-like finish or leaving them worse than before.

The first question to ask when determining which grinder is right for you is: What is your skill level? For beginners, we recommend a 3,500 RPM variable speed grinder. Variable speed polishing machines are excellent for adjusting your speed through different polishing stages. For instance, during the cut and color stages, use a 9" orange airway with a tripoli bar (cut stage) and a 9" yellow airway with a tripoli bar (coloring stage) at the full 3,500 RPM. For the final step, which involves a 9" domet flannel airway and a purple polishing bar, slow down the grinder to about 1,800 RPM. This variable speed feature is fantastic as it gives you better control over the finish. Slowing down the polisher for the final shine minimizes the risk of burning or hazing the aluminum due to excessive heat from higher speeds. We highly recommend the Makita C or the Makita GA, both of which are excellent choices, depending on the best deal available at the time.

Once you master the art of polishing—if that's even attainable—with proper pressure, angles, and products, you can then move on to more advanced machines that professionals use. Nearly all professional polishers we know utilize the Makita GA, which is a fixed speed 8,000 RPM buffer. When a buffing wheel is attached to this buffer, you'll achieve an industry-standard speed of 6,000 RPM. Most professional polishers use this fixed rate for both the cut stage (orange wheel/tripoli bar) and the color stage (yellow airway/green rouge). However, when working with a flannel or cotton buff, professional metal polishers typically revert to a 3,500 RPM polisher to enable lower speeds.

It is essential to consider the maximum safe operating speed for each size of buffing wheel. We always advise using safety flanges during polishing, whether using insertable flanges instead of center plates or exterior flanges for buffing wheels. All machines mentioned above feature a 5/8" arbor shaft, compatible with all 5/8" arbor hole airway buffing wheels manufactured here at Renegade Products.

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Summary of Aluminum Polishing Machine Recommendations:

Best grinder for professionals: Makita GA

Best grinder for beginner polishers: Makita C

Absolute necessity for safety: Flanges

Best polishing kit with sanding supplies: Big Rig Restoration Kit

Best aluminum polishing kit for beginners: Aluminum Polishing Mini Kit

Recommended equipment: Full Face Respirator Mask

To clean surface rust off chrome, I often use a piece of aluminum foil along with Windex or Coca-Cola, as the acid in these solutions helps dissolve rust. This method works well because aluminum is much softer than chrome, preventing scratches or swirls. Steel wool is too hard and tends to leave swirls. I’ve noticed that the aluminum leaves a protective seal in larger pits and scratches on my forks, preventing rust from reappearing, which is also true for mufflers and fenders.

Consider trying this method. If you think it’s effective, then continue using it. However, if you believe that commercial products labeled "chrome polish" are necessary, feel free to invest in those. Keep in mind that they are not designed to remove rust or pitting but rather to polish out minute swirls, remove contaminants, and leave a micro-thin protective film for easier maintenance next time.

Curious about polished tiny rusty pits? I suggest trying out my previous cleaning method with aluminum foil. If it works for you, that’s great. But if you feel the need to buy polish, go ahead. Just know that the commercial products mostly serve to polish rather than fix deeper issues.

Want more information on the Chrome Polish Machine? Feel free to contact us at pt, tr, or es.