2. Operating modes

2.1 Pure welding

• Surface tension phenomenon

  From the moment the metal is brought to fusion, capillary action becomes essential.

  As with other processes, in most cases the operator has visual access to only one side of the parts to be joined. A liquid solder bath must therefore be maintained in equilibrium:

  • deep enough to reach the full thickness;

  • not too wide so as not to exceed the possibilities of the surface tension, which acts like a membrane supporting the liquid bath between points A and B (figure 3 ).