Apply flux

Apply a chemical cleaning agent, such as ammonium chloride, rosin, hydrochloric acid, zinc chloride, borax, and others, that removes the oxidation from metals being joined during soldering, brazing, and welding processes.

handle flux
administer solder cleanser
administer flux
utilise solder cleanser use solder cleanser
utilise flux use flux
handle solder cleanser

skill/competence

cross-sector

Apply flux is an essential skill of the following occupations:

Solderer: Solderers operate various equipment and machinery such as gas torches, soldering irons, welding machines, or electric-ultrasonic equipment in order to solder together two or more items (usually metals), by melting and forming a metal filler in between the joints, the filler metal has a lower melting point than the adjoining metal. 
Brazier: Braziers operate various equipment and machinery such as torches, soldering irons, fluxes and welding machines in order to join two metal pieces together, by heating, melting and forming a metal filler inbetween them, often brass or copper. Brazing can join metals such as aluminum, silver, copper, gold, and nickel. Brazing is a similar process to soldering but requires higher temperatures. 

Apply flux is optional for these occupations. This means knowing this skill may be an asset for career advancement if you are in one of these occupations.

Welder:
Welders operate welding equipment in order to join metal workpieces together. They can use fusion welding processes based on different techniques and materials. They also perform simple visual inspection of welds.
Rolling stock assembler: Rolling stock assemblers use hand tools, power tools and other equipment such as lifting equipment or robots to construct, fit and install prefabricated parts to manufacture rolling stock subassemblies and body structures. They read and interpret blueprints. They operate control systems to determine functional performance of the assemblies and adjust accordingly.
Motor vehicle body assembler: Motor vehicle body assemblers fasten motor vehicle body parts and components together such as frames, doors, chassis and hoods. They use hand tools, power tools and other equipment such as CNC machines or robots. They read technical plans and use automated assembling equipment to build motor vehicle bodies. They inspect individual parts for malfunctions and check the quality of assemblies to make sure the standards are met and the specifications respected. Motor vehicle body assemblers report any assembly issues to their supervisor.

References

1. Apply flux – ESCO