Title: Refrigeration Brazing and Soldering

You can stop watching the video here. If you continue: wetting of the filler metal on the base metal is indeed the cause for the capillary forces that drag the liquid filler metal into the joint. However, the sketch of the mechanism for propagation of the liquid front into the gap is wrong (min 2:10. there is no oscillation of the surface curvature – it is always concave. The Optional Resources show a video explaining capillary action).

Choose the correct statement.