Metal finishing Q&As since 1989

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Procedure for mirror finishing naval brass for 99.9% reflection

2003

DEAR SIR,

I AM MANUFACTURING AN ELLIPSE SHAPED REFLECTOR. IT IS DIVIDED INTO TWO PARTS, UPPER HALF ELLIPSE AND LOWER HALF ELLIPSE. THE BASE MATERIAL IS NAVAL BRASS. I AM TELLING YOU MY REGULAR PROCEDURE OF MANUFACTURING ELLIPSE: ELLIPSE IS MADE USING WIRECUT MACHINE.THEN I USE BUFFING PROCESS FOR GETTING MIRROR FINISH AND THEN I COAT IT WITH THREE DIFFERENT MATERIALS-- NICKEL , PALLADIUM AND FINAL GOLD COATING TO ACHIEVE 99.9% REFLECTION. AS PER MY KNOWLEDGE, FINAL REFLECTION DEPENDS ON THE FINISHING BEFORE COATING. I AM NOT ACHIEVING 99.9% REFLECTION . I WANT TO KNOW THE EXACT PROCEDURE FOR MAKING THE NAVAL BRASS MATERIAL TO A MIRROR FINISH BEFORE COATING.

PLEASE HELP ME AS SOON AS POSSIBLE .

THANKING YOU,

BHADRESH V PATEL
- SURAT, GUJARAT, India

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I cannot answer your question with the information given; however, I have a question for you. Do you have any idea of the surface profile of the metal you are using? The finer the RMS of the metal the better the plating RMS.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2003

I do not know how you measure reflectivity, but I will be surprised if you can get "true" reflectivity above 80 or 90% on gold no matter how much you polish. Gold absorbs light significantly more than, e.g., aluminum or silver. Aluminum will give you about 97% reflectivity at the best.

Mandar Sunthankar
- Fort Collins, Colorado
2003

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I'm not talking about reflectivity. I am just trying to get him to look at the surface finish of the metal. Basically, the smoother the profile of the metal under any plating determines the smoothness of the top surface as well, which should translate into reflectivity.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2003