As a large supplier of tin strip chemistry I can tell you that your nitric chemistry should hold about 150g/l tin, 20g/l iron, and 10g/l of copper. The chemistry should not contain any chelaters and most large customers simply bleed this into their non chelated metal bearing waste streams. A tin strip consumption of 1 drum a day would mean that you would only need to feed 2 gallons an hour to your waste stream. This dilution is usually helpful. I would check the level of copper in the spent chemistry and if it is over 12g/l you are etching excessive amounts of copper. The etch rate on a broken in bath should be only 10 - 15 millionths/ minute. Regards, Chris McGary Dexter Electronic Materials *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************