Traditionally, brazing and soldering are distinguished from each other in the following manner:

• Flame soldering of aluminium: TL < 450 °C
• Flame brazing of aluminium: TL > 450 °C

There are some common guidelines which should be followed in order to achieve successful soldering/brazing:

• Joint clearances
• Cleanness
• Selection of flux and filler material

Flame brazing with an AlSi filler has a narrow process window, approximately 20 °C, and there is a need for good temperature control to avoid scrapping of the joined parts due to overheating. Flame soldering, using a ZnAl filler, has a much wider process window than experienced by AlSi flame brazing, which gives allowance for higher temperature variations without damaging the quality of the joint or the tubing. However, the presence of zinc makes the joint appear less noble than the rest of the material which is the cause for galvanic corrosion. To avoid this problem, the joint may be sealed by applying an epoxy coating, heat-shrinking plastic wrap or similar. The soldering method can not be combined with ammonia refrigerant (NH3) since the zinc will be attacked.