Thanks Dave - customer has not done any testing and for years we have only used no-clean for both operations so now I have some parts to be done one way and some another for Class 3 medical. Not good in my 2 cent opinion. Regards Steve Kelly From: [log in to unmask] [mailto:[log in to unmask]] Sent: June-20-13 9:15 AM To: TechNet E-Mail Forum; Steven Kelly Cc: TechNet Subject: Re: [TN] Mixing solders, Hi Steve - I'll have to pay Doug and use his tag line - "It depends"! Anytime you mix two different flux systems, especially a water soluble and a low residue (aka no clean), there may be an issue of incompatibility that could result in a really hard lacquer (best case) or a really cool corrosion cell (worst case). My recommendation would be to advise the customer that the mixing of the two flux systems would not be advised unless some testing can be conducted to ensure no detrimental reactions would occur. A second option would be to check with the flux supplier to see if they have any compatibility data. If the fluxes come from two different suppliers, don't waste your time asking that question as they won't have the answer. Good Luck. Dave Hillman Rockwell Collins [log in to unmask]<mailto:[log in to unmask]> From: Steven Kelly <[log in to unmask]<mailto:[log in to unmask]>> To: <[log in to unmask]<mailto:[log in to unmask]>> Date: 06/20/2013 08:02 AM Subject: [TN] Mixing solders, Sent by: TechNet <[log in to unmask]<mailto:[log in to unmask]>> ________________________________ Hi All, I have been looking in the archives but can't seem to find what I want an answer to . I have a customer who wants us to use water soluble RoHS for the SMT process but wants no-clean RoHS for the touch-up. Is this recommended? Regards Steve Kelly If the recipient to whom this e-mail is sent has an NDA with PFC Flexible Circuits Limited this e-mail is considered confidential and is subject to any NDA agreements between the respective parties. See PFC on "How It's Made`` coming soon on the Discovery Channel! ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask]<mailto:[log in to unmask]> ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________