Hi Jan: Please don't take this wrong but why are you brewing your own flux? There are dozens of flux formulations on the market that you could try that have enhanced activity to solve solderability problems (but sometimes at the expense of corrosion problems). Interflux is good stuff but you need only enough to do the job and must get it totally cleaned off. What is the nature of the solderability problems? It sounds like you are preheating the assembly for a very long time or that you have very small vias you are trying to fill. Can you give fill in some more details on the specifics of the solderability problems? Are you using nitrogen? Is the assembly big? Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Wave soldering flux problems Author: [log in to unmask] at ccmgw1 Date: 7/1/96 6:55 AM Hi! We're using a SEHO nitrogen wave soldering machine and are experience a problem with solderability on boards and components. Now we are testing a new mix of flux. We're mixing 50% of a no clean flux (Interflux IF2005M) and 50% destillated water and an additional 2% adipic acid. The theory of this is that the alcohol won't evaporate as fast as it does and the flux have more time over the preheater to "crawl" into the plated holes. The solderability increased and the joints was less crystalized. But the problem was the contamination. It also increased from a factor of 0,10 to 0,70. Our standards are below 0,15. Has anyone tried anything similar or have any theory why the board contamination increased that much? We have a theory that it wasn't the acids fault but the board. The original flux also have a 2% solidcontent. /Jan Merstrand e-mail: [log in to unmask] [log in to unmask] fax: +46 33 179669