The authoritative public forum
  for Metal Finishing since 1989
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SURFACE CONDITION BEFORE FINISH

Dear all,
Nice to meet you here, I am encountering some problem on surface finish, the product of our company manufacture need to do some surface finish, as chemical clean, electropolish, passivation, anodize, paint, etc. before do these treatment, the surface condition of metal need to reach to requirement so that after surface finish, the cosmetic can reach to spec of drawing, my problem is before surface finish, what surface condition can reach to spec of drawing after surface finish. I want to know if there is specification to request the cosmetic of metal before do surface finish.

WangChangHong
- SuZhou, JiangSu, China
2005

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I'm not sure I understand your question, but let me say this as a generality. Finishing can be divided into 2 separate divisions. They is surface preparation and surface protection. The first has to do with surface improvement. The second is a final protection or coating. The smoother the surface preparation the finer the appearance of the fished part will be. I hope that answers your question.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2005

Thank you for your advice on my question. My problem belongs to the first division your statement, what I need to know is how to do surface preparation before performing second treatment, whether we can get some inspection standard according to surface requirement after finished. thanks again!

WangChangHong
fox - SuZhou, JiangSu, China
2005

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Still not sure what you are looking for. If you want to specify a surface finish prior to a chemical treatment or plating then the answer is yes. It can be shown on a drawing as an RA, RMS, or any other standard as long as it is referenced. That also goes for the surface coating. Typically, most non-ferrous parts are surface finished to 16-18 RMS for andizing. Ferrous depends on the final coating.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2005

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Your customer should be able to provide a surface preparation standard or sample parts to match. Experience will allow yu to make this determination without this kind of guidance. I suggest you contact your anodizing or electroplating vendor to receive assistance in this area, or employ a consultant to get started.

Daryl Spindler, CEF
decorative nickel-chrome plating - Greenbrier, Tennessee
2006