Kester Flux Pen #951 Low Solids No Clean
Storage and Safety
For best results and longevity of this product, please keep your flux pen in a refrigerated environment. If kept at room temperature, the pen should last and function properly for about a year.
The Science of Flux
“…In high-temperature metal joining processes, the primary purpose of flux is to prevent oxidation of the base and filler materials.
Flux is a substance which is nearly inert at room temperature, but which becomes strongly reducing at elevated temperatures, preventing the formation of metal oxides. Additionally, flux allows solder to flow easily on the working piece rather than forming beads as it would otherwise….
…The role of a flux in joining processes is typically dual: dissolving of the oxides on the metal surface, which facilitates wetting by molten metal, and acting as an oxygen barrier by coating the hot surface, preventing its oxidation. In some applications molten flux also serves as a heat transfer medium, facilitating heating of the joint by the soldering tool or molten solder.”
excerpt from “Principals of Soldering” by Giles Humpston, David M. Jacobson