Immersion Tin works reasonably well if there is Copper or Lead exposed to cause plating to occur...if these metals are not available, the Immersion Tin is little more than a dilute acid wash. Rudy Sedlak RD Chemical Company "<Richard Edgar>" <[log in to unmask]> wrote: The best method would be to place the boards into an immersion tin bath. The immersion tin bath is acidic and will remove any oxide/hydroxide finish from the surface. For over 40 years immersion tin has been used in the electronic industry. One of its uses was to "refresh" a solder surface. Oxide coated tin/lead finishes were cleaned and recoated with a thin coating of tin. In this application it will easily refresh yours. You might want to consider using one of the new "immersion white tin" chemistries since they will coat any exposed copper that might have appeared. . Rich Edgar Tec-Line Inc. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts 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 ----------------------------------------------------- --------------------------------- Do you Yahoo!? --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts 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 ----------------------------------------------------- Read only the mail you want - Yahoo! Mail SpamGuard.