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Q&As since 1989


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POLISHING ALUMINIUM

DEAR FRIENDS, WE ARE HAVING A PROBLEM IN ALUMINIUM COOKWARE POLISHING. AFTER ECHANICAL BUFFING,EMERY POLISHING WE ARE NOT GETTING THE REQUIRED MIRROR FINISH POLISHING. ALSO SOME SCRATCHES ARE NOT GOING IN POLISHING.THIS DEFECTS REFLECTS AFTER ANODISING FINISH,SO HELP US IN IMPROVING THE POLISH FINISH BY LATEST METHODS OF POLISHING OR CHEMICAL POLISHING IS THERE,PLS RECOMMEND US THANKS D.ELANGOVAN

ELANGOVAN DAMODARAN
- INDIA
2000

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Greetings Sir,

I would ask myself a few questions before I answered this one.

1.) How is the material formed, is it stamped, spun, deep drawn? These all affect the material and what it is capable of having done to it.

2.) Chemical Polishing - Its a beautiful process for aluminum, dependent upon the material you have and the type of forming that was used to achieve the finished product.

I have electropolished parts from a 3000 series material and they have a shine and reflectivity (not to mention a smoothness) that far exceeds the abilities of mechanical buffing/polishing. The limitations on this process being that the material cannot exceed 2% silicon concentration. If you know the material type you are working with and it doesn't exceed that limitation you should explore chemical polishing of some type. I would suggest a place here in the U.S. but that would not be beneficial to you with regards to your location. If you can find someone that either processes aluminum chemically or a supplier of a product, you should send them 1-5 pieces of the problem part and ask them to sample them for you and see the results, you may be very surprised and also you might save yourself a considerable amount of time and headache if you only have to chemically polish them.

Matthew Stiltner
plating company - Toledo, Ohio
2000

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2000

Mr. Damodaran

Mr. Stiltner's response, or rather suggestion, is indeed one of the better ways to go, but, if not possible or practical, mechanical polishing is the only alternative. I supply the commercial aviation industry with specialized polishing equipment, techniques and polishes (since 1989). We recently received a request from a local restaurant supply distributor to see if we could help in a problem he had (has) with imported pots scuffed in transit. We were oddly enough contacted because these pots are (apparently) made from 6060T6 "CLAD" aircraft aluminium. To date they are extremely pleased with the results, (extreme high reflectivity) using a product called ROLITE AP300 with 8" (20cm) flannel spiral sewn buffing wheels at 1700 - 1800 rpm. I only cover the CANADIAN market. I know no one is carrying this product in India but it works.

Regards

Paul Embury
distribution - Montreal (Hudson), Quebec, Canada

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Being n the metal finishing industry for some time I have found that Canton Flannel leaves virtually no lines when accompanied by a chromium oxide or a calcide Alumina bar, I would recommend a sewn buff if the scratches can be felt by a finger nail or a loose (unsewn buff) or an airway configuration, this would also depend if you are using them in a hand application or an automatic or semi-automatic.

If you are going through the process from start to finish then there are a different set of parameters that would come into effect.

Doug Dunlop
- Georgetown, Ontario, Canada
January 9, 2008