• Beading indicates that an intact coat of wax protects the vehicle's surface.Beading on Red Car image by emiria331 from Fotolia.com
  
  A car's surface can retain its luster and resist weathering longer when protected by a coat of wax. The included instructions on many commercial car waxes are a good indication of their effectiveness against the elements. However, testing can reveal additional properties of specific waxes and their effectiveness on various automobile surfaces.
  
  

Testing for Beading and Sheeting

• Water tends to bead on a waxed surface because it adheres more easily to itself than it does to the wax. When water beads on black or dark surfaces, it can leave small droplets behind which create water spots as they evaporate. Auto owners who wish to avoid spotting may seek a wax from which water runs off more quickly, forming sheets instead of beads, to avoid this effect. A variety of waxes are designed to encourage sheeting instead of beading, and these can be tested by applying small amounts of wax to the automobile's surface and observing water's tendency to bead or sheet on the waxed surface. Water is more likely to sheet under conditions of heavy rainfall or fast accumulation, such as that which occurs when using a garden hose. Using a spray bottle or hose set to low water flow will reveal the wax's ability to sheet under light rainfall or mist.
  
  

Testing for Gloss or Shine

• The level of gloss or luster achieved by waxing may also vary between types of wax. As with testing a wax for sheeting, testing for gloss and shine is also accomplished by waxing a small surface on the vehicle with wax and comparing it to the unwaxed surface around it.
  
  

Testing for Longevity

• Some newer synthetic waxes may last up to a year between applications, and cars that have been regularly waxed tend to retain new applications longer than those which have not. Testing a specific wax for longevity is simply a matter of observation. To determine the maximum length that can pass between applications of a specific wax, simply observe its effectiveness over time. The desired beading or sheeting will diminish as time passes, and this will help determine the intervals at which to apply new wax coats.
  
  

Comparison Tests Between Waxes

• Comparisons between multiple waxes are accomplished simply by applying different waxes to multiple adjacent sections of the car's surface. A wax pencil can mark the boundaries between different test surfaces, after which each wax can be applied.