Tenacity™ No.4A Flux Powder is a medium temperature brazing flux suitable for use with silver brazing filler metals. It has a working range of 600-850C and is suitable for use with silver brazing filler metals that melt below 800C.
It is useful for brazing larger assemblies in steel or copper wherever prolonged heating may cause general-purpose fluxes to become exhausted. It also finds applications in silversmithing.
Product uses:It is suitable for use on all the common engineering materials (copper brass mild steel and stainless steel) but not aluminium. JM special purpose fluxes are required when brazing aluminium bronze certain grades of stainless steel tungsten molybdenum and tungsten carbide.
Conditions for use:Tenacity™ No. 4A Flux Powder should be mixed with water and a few drops of liquid detergent to form a thick paste. Paste should then be brushed onto the joint surfaces before assembly. Further flux should then be applied externally either side of the joint mouth.
It is good practice to mechanically clean and degrease the joint surface before applying flux. Heat slowly and evenly to the brazing temperature without local overheating. Use the flux as a temperature guide - it will become clear or opaque as brazing temperature is approached. If blackening of the flux occurs this is often a sign of insufficient flux overheating or flux exhaustion.