Kester 979 is a VOC-free, no-clean flux formulation for high quality, low-defect soldering of electronic circuit board assemblies. This flux\'s finely tuned activation system offers the best wetting available in VOC-free liquid flux technology and the shiniest solder joints. 979 also reduces micro solderballing on glossy laminates and between connector pins. 979 will not attack properly cured solder masks or FR-4 Epoxy-Glass laminate. 979 leaves a minimal amount of residue after soldering. All remaining residues are non-corrosive, non-conductive and do not need to be removed