Good idea. This will additionally confirm if the cure of the mask is an issue. I have some experience with the alkaline ingredients of an OAWSF attacking uncured mask. If this is the case, the alkaline wash recommended below may also attack the mask. Even if not, the flux may still be an issue because if you combine the alkalinity of the flux ingredient with the preheat temperatures seen, you could have the required synergy to attack borderline acceptable mask. Rich Kraszewski Advanced Manufacturing Engineer - KEDS Phone: 260.925.8919 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Rudy Sedlak Sent: Thursday, April 22, 2004 2:32 PM To: [log in to unmask] Subject: Re: [TN] White Discoloration -- Tin? I come in on this discussion late, so I am not aware of previous parts, but has anyone yet suggested the possibility that the white haze is Tin Oxide from the solder dross? IF this were the case, a wash with a strongly alkaline cleaner might make it go away... Rudy Sedlak RD Chemical Company --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------