Summary for buffing problem on brass Discussion
buffing problem on brass appears to be causing small pinhole-like spots during finishing, forcing extra grinding and adding cost. Uday Bakrania says the issue has developed over the last year in production, while John Reid reports a similar problem that has worsened over five years and believes poorer recycled brass with more impurities may be a cause. John’s practical suggestion is to minimize brass temperature during polishing and let parts cool to room temperature between operations, though Uday notes that approach is hard to use for high-volume runs of 2000+ pieces every three days. In a later question, Uday asks for a non-buffing method for mirror polishing raw brass. Ted Mooney replies that brass can probably be brightened with copper bright dips such as sulfuric acid plus stabilized hydrogen peroxide, but cautions that true mirror polish likely still requires mechanical mirror polishing.
Hello,
We are running a industry from last 20 years in India. We work with brass metal. In last 1 year we are facing problem in the buffing process. While finishing our product with buffing process small pin holes type spots are appearing on metal. These are than removed again with grinding on 600 belt. But it costs lots of time and money.
Uday Bakrania
Manufacturer – India
August 25, 2011
We have a similar problem here, and it’s been getting worse over the past 5 years or so. I believe it’s because the quality of the brass is becoming poorer the more times it’s recycled (more/varied impurities).
One way we’ve found to deal with it is to minimise the temperature of the brass when polishing. After each operation, allow the parts to cool back to room temperature before starting on the next. Often this happens naturally in the course of undertaking the job if there are many parts; however if there’s only a few, have your worker set them aside to cool and start on a new job.
John Reid
– Brisbane, Queensland, Australia
August 30, 2011
Thanks for your reply.. but I’m in production of 2000 or more pieces per 3 days… isn’t possible with this method.. can you suggest me something else..??
Uday Bakrania
– India
September 7, 2011
Q. Can you suggest me a method for polishing raw brass except buffing; I need alternative method for mirror polishing.
thanks
Uday Bakrania
– Jamnagar, Gujarat, India
April 24, 2012
A. Hi Uday.
You can probably brighten brass with copper bright dips like sulfuric acid plus stabilized hydrogen peroxide. But I doubt that it is possible to mirror polish without mechanically mirror polishing.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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April 24, 2012
A. Sir,
Thank you for your reply. But I didn’t understand what you have written, can you elaborate please?
Uday
Uday Bakrania
– Jamnagar, Gujarat, India
April 26, 2012
A. Hi.
I am saying that if you want your parts to look like they are buffed then you must buff them :-)
To my knowledge there is no alternative.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.