Bright dip for brass silver articles

Hi Donvan

Many thanks for your advice on bright dip for copper.I am pretty sure that it
will work out well.Will give you the feed back after the trials
thanking You
rajaram60

Rajaram60,

FYI-
As with many other bright dip processes, the reaction that takes place between the part being processed and the Nitric Acid in the tank can create a dark reddish-brown NOx plume.  NOx is a biproduct of the reaction, which consists of Nitric Oxide and Nitrogen Dioxide gases.  Nitrogen Dioxide gas is toxic and potentially lethal by inhalation.  Long term exposure can cause adverse respiratory conditions. 
The tank should be ventilated with a properly designed local exhaust ventilation system made from chemical resistant materials such as PVC.  Since the plume is visible you'll probably want to scrub it as well so the neighbors don't complain.  The smaller the tank, the better.  I know it sounds expensive, but I'm sure you know since you also hard chrome plate. 

In a lab environment, just make sure the fumes are carried away by a lab hood.  The NOx gas is generally only created while the part is being processed.

Good Luck,
Kyle Hankinson - CEF
www.kchservices.com