PCBs

Q. I am seeing a white powder around solder joints on PCBs.  Is this solder flux? We use Detergent 8 for cleaning. Do you know why this is happening and how to stop or remove it?
A. There are several ways of approaching this common issue of solder flux and its removal. For example, One way to fix this problem is to lower the temperature when soldering. In another scenario, a leading aerospace manufacturer studied putting potassium silicate (10 mL in 10 L) into the Detergent 8 bath to act as an inhibitor to stop the formation of these white salts.

Is Alconox and/or Liquinox an effective detergent for rinsing and removing polychlorinated biphenyls (PCBs) from non-porous surfaces (such as excavation equipment)? We have a great deal of experience with remediating PCBs with both powdered and liquid concentrate detergent options.