Flux is a solid shielding and cleaning material placed on metals involved in welding to purify, optimize flow and prevent oxidation in the weld or solder joint. But flux can create slag and weld spatter. Grinding, drilling or possible rewelding are then required to remove the slag. Also, welded areas where flux has caused weld spatter/slag may result in non-conductive spots that will not accept paint coatings. So there are some welding and soldering applications where flux is not a benefit. There are two options for removing flux: grind it off the surface, or use a special chemically formulated flux remover. Flux remover sprays and solvents dissolve flux and rinse away flux residue that can cause welds and soldered joints to corrode or short circuit. Flux removers vary by size, applications system and other considerations.