Capillary action

From GAWDAwiki

Capillary action is the process by which liquid is drawn into the joint by molecular attraction. Capillary action can operate against the force of gravity. Brazing and soldering rely upon capillary action to draw the filler material into the joint. ^[1]

References

1. http://www.bocindustrial.co.uk/bocindustrial/technical/glossary/a.asp