>From the EMPF HelpLine; prepared by Pat Kane:

The term solder splashes could refer to anything from solder balls
to bridging.  One possible thing to try would be to experiment with the
amount of flux applied to the pcb.  If there is excess, and the preheat does
not activate it completely, then the excess will boil away (splash) at the
entry to the wave bath.  This is only a first guess, I would need more info
i.e. what are the preheat temps achieved on the topside? What type of flux?
What is the conveyor speed? Where are the splashes occurring? Is the problem
consistant from board to board or random? Do othe assemblies demonstrate the
same problems?  Let me know if you get answers to any of these.

>>>Presently we are seeing accurrances of solder splashes in our wave solder
>>>process. We have PCB's that are less then three months old and our storage
>>>process is inside of a ziplock bag with desiccant. Our present environment
>>>has a higher than normal humidity level of 40 to 50%.  We have attempted
>>>many adjustments to the proces such as speed, flux gravity(foamer), etc..
>>>The only thing that appears to eliminate or reduce the splashes is baking
>>>the assembly for 1 hour at 50 degrees 'C' and doing the wave process while
>>>the assembly is still hot.
>>>
>>>Does anyone out there have any ideas of what could cause this problem or
>>>things we should try that could eliminate them?
>>>
>>>Thanks in advance

                      Jack Crawford
                  HelpLine Manager
    Electronics Mfg. Productivity Facility
                     317.226.5616
               Visit our homepage at:
                http://www.empf.org