Hello all, We use plastic coated stainless steel plating jigs for copper and tin- lead plating. When they start to plate over the plastic coating, we strip in a 50% nitric acid solution unheated. After a while the racks become coated with a white precipitate of tin and lead salts which are seemingly impossible to remove. Q1 Can anyone advise how to prevent this precipitate forming eg does a proprietary stripper eliminate this. Q2 Is there a chemical method of removing it without exceeding 122F (50C). Thanks for any assistance. -- Paul Gould [log in to unmask] Isle of Wight,UK ############################################################## TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################