Adam - Sorry, I misread your second question - no mask to be applied. Stripping the tin will mean no copper/tin intermetallic can be formed in storage. Think then the question for you is whether your assembly system flux is more compatible with tin, or with bare copper, probably protected by Organic Solderability Preservative (OSP). Denny Fritz --------------------------------------------------------------------------------- Technet Mail List provided as a free 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 Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------