Hi Ramsey, Did you eliminate the problem? What's the fix? We have wanted to switch to a water soluble mask. This might be the perfect 'motivation' for me to do a validation test. Hans > We experienced intermittent corrosion after wave solder at land patterns > that had been protected by temporary latex solder mask. We discovered > that the natural latex, low ammonia, types were less conducive, but > would still produce corrosion. > The variable in the process seems to be thickness. The mask should be > applied in as thin a layer as possible. Thick mask must trap ammonia > under the mask. Baking a thick layer of the mask seems to make the > problem worse. Since the mask skins over the board and protected land > pattern are baked in ammonia corrosion results. ############################################################## 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. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################