Sentence:  As a final test of whether the base object has been cleaned of all dirt and grease, observe the form carefully while it is being rinsed to observe the <WSD>waterbreak</WSD>. If the water runs smoothly over the object in a uniform sheet there is no <WSD>waterbreak</WSD>, and the form is probably sufficiently clean to plate. 
Meaning of the word marked with <WSD> tags:  The formation of beads of water on a smooth surface, especially when used as an indicator of impurities on the surface.