Hi Tom The only flaw in your premise is the second part of number 2 - how are you sure you have removed all washable flux residue? No flux residue under low clearance components? None stuck under connectors? Magic! It comes down to: - how clean is clean enough (end use environment, reliability requirements) - what do you have when you mix no-clean with a bit of residue from an OA or other type of flux? It is easier to sleep nights if you don't mix flux. You may not have a problem with cleaning and then using no-clean, but it's easier to be sure if you can use no-clean for everything. regards, Graham Collins Process Engineer, Northrop Grumman Canada Corporation Halifax (902) 873-2000 ext 6215 >>> [log in to unmask] 03/11/03 12:39PM >>> I've read the recent questions and information concerning mixing of fluxes. I agree - do not mix flux types when soldering. However, here's one for you that can be looked at from a couple of angles.... 1. I build a board - wave solder using washable flux. Flux is activated, does it's thing, and board is soldered. 2. Water Wash and Dry the board. All washable flux residue is gone. 3. Add a couple of more components that CANNOT be washed (water will enter the component and ruin it), using NO-CLEAN. 4. Board is done. Technically, I have used 2 types of fluxes on one assembly.... Another scenario: 1. Board (described above) is finished. But, fails test - I find a bad component... 2. I have to use NO CLEAN to replace the component because I cannot water wash the board (remember the other components that cannot be subjected to water wash..) 3. Board is done. Passes test - finished. Again - Technically, I have mixed fluxes on the same assembly. In the above description, I do not see a problem - or am I missing something? Thanks, Tom --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------