Dear Technetters, periodically we are having problems with a dull, brownish discoloration of our electrolytic gold. The discoloration is independent of whether the gold is being plated on electrolytic or electroless nickel. LAB-analysis´ has been within spec´s each time. I have been proposed that the cause could be bleeding of the photoresist due to locally rise of pH > 9 in the plating bath. Roundpumping (eventually through a carbonfilter) could level the pH in the bath, but could this lead to other problems ? Have any of you experience with this ? With best regards CHEMITALIC A/S Jan Thuesen Process Engineer ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################