Beading is the forming of water into bead like bubbles on the surface of the vehicle. The bubbles are formed due to the HYDROPHOBIC qualities of the Last Stage Protection applied. A vehicle which has been thoroughly and correctly prepared will not necessarily show equilateral beading, but will sheet water well. It is due to the surface water having no contaminants to cling to. The better prepared and protected the paint work is, the greater the beading, and the greater the durabilty of the protectant due to the greater bond between the surface and the last stage protection. It can be such that the beads form patterns and in the winter you can see the water crystallize above the paint surface.
When the vehicle is in motion the water beads will blown off the car. This is known as sheeting. It is similar to a sheet of paper or a cloth sliding down and off the front of the bonnet. The water reacts in a similar fashion, and you will see that from pouring a jug of water over the body work, the water will sheet off leaving the odd 1 or 2 water spots. On a poorly, or even untreated surface, the water will cling to the surface.
Dependant upon the level of surface preparation and the quality of the protectant use a drop of HYDROPHIBIC qualities does not indicate a reduction in surface protection. Some hi quality products will provide protection upto and if not beyond 2 years, however, some will show a reduced HYDROPHOBIC function after a few months.