Hi Larry, Chris, Dennis, , , IPC LF Listservers, Well I read everyone's notes and I come back to one part of your question. <I have a customer who wants us to build a board to help him validate lead free.> validate to me usually means leading to full manufacturing qualification. Since you might have to live with his/her validation I would try to understand what they are trying to validate and maybe how this might be to your detriment. You already received some good answers here on your topic and on another topic of Solder Dross and Solder Pot maintenance i.e. "Lead-Free Dross in Wave Solder systems". Among items to consider is the reduced MSL ratings i.e. floor and shelf life for certain SnPb era plastic encapsulated componentry. I mean you are going to go about 34 degrees hotter. I do understand how the Japaneese did their mixed processing for consumer products yet I believe that was a consistent mixing with high volume, low reliability, low return products that didn't need the full 34 degrees. Yours in Engineering, Dave Y i Engr, MA/NY DDave -------------------------------------------------------------------------------Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Leadfree To temporarily stop/(start) delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL/(MAIL) Search previous postings at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -------------------------------------------------------------------------------