I would like to know what will be the best way to clean sludge inside solder stripper chamber. we are using HNO3 based chemistry and we tried different way like HNO3 with HCl or Sodium hydroxide with sodium glyconate, still it is difficult to remove all those sludge which not only short the bath life , but also cause salt stains on the copper surface, even mild microetch has difficult to remove those white salt spots. Any good suggestion? By the way compare to Sn-Pb solder resist, The pure tin seems more easy generate the sludge. *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************