if u think humidity might be a cause - try drying the boards in an oven for 20 minutes at 250F . Then try cutting out a section and perform a solder float test - floating coupon in a solder pot. If you get blowholes - outgassing - would start sectioning boards and looking at copper walls in general - it might just be ur boards. Regards Richard Fudalewski Atotech Canada ################################################################ 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 web site (http://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################