Hi Paul - We asked this same question of our connector suppliers about a year and a half ago. We also asked the question of compatibility with bare copper (for OSP coated boards). Both of the responding suppliers were able to tell us that they had performed Bellcore outdoor environmental testing on their products using these finishes, and passed the test series. The specimen reportedly had heavy levels of "corrosion" buildup visible where the pins entered and exited the plated thru holes. I was never able to get a fully detailed report or photos to be able to differentiate between finishes. Would recommend you get with applications engineering at your supplier to see what data they are able to provide, first hand. Regards - Kelly ################################################################ 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 ################################################################