The use of silicones as used in certain types of liquid polishes is much more durable than wax base polishes. The solar convection heat will melt the wax that lays on the painted surfaces. Because waxes are hard and viscous, they plate over the surface and do not penetrate into the pores. Waxes have very little resistance to detergents and are easily washed off. When left out in the sun, the exposed surfaces quickly heat up. The wax melts and, while in a molten state, dust, industrial fallout, exhaust fumes and other pollutants floating in the air are absorbed into the molten wax. The end result is that the paint is washed more often which will then exposes the surface to many more destructive elements: ultra violet and infrared rays, acid rains, etc.
The best-known waxes (camuba) widely used over beeswax are no match for the degradation of the natural elements and manmade pollutants. Waxes must be constantly applied to maintain a good protection.
Silicones were first introduced in a liquid polish for autos, planes and boats in the mid-1950’s. They were easy to apply, had a greater depth of shine and endured many times longer than waxes. Silicones had a lot going for them, but they also had drawbacks that created nightmares for the paint shops.
Silicones “crosslink” and “bond” onto the painted surfaces and penetrate into the pores. It is this penetration that has given paint shops so much trouble. Every time the surface is washed, it drives the silicone deeper into the paint. It will continue to “drift” down into the prior coats and eventually into the body metal.
As the silicones penetrate or drift further into the painted surfaces, they leave the surface exposed to elements just as waxes do when they melt or are washed off with a detergent. Depending upon the season, waxes will endure in the summer months for about 5 – 8 weeks whereas silicone will hold the protection for approximately 6 – 12 months, depending upon the quality of the silicones and how they are formulated. Their demise eventually comes from their ability to drift. They, too, will drift all the way to the metal.
Once silicones have permeated the paint, the primer and the metal, a painter cannot get his paint to properly adhere. The silicones make the new paint “foam” which causes minute pockets of air in the newly applied paint. This is called “entrapment”. As the paint is curing and the solvents are flashing off, the tiny pockets of air slowly work their way to the surface and create what is called a “pinhole”. Sometimes these entrapped air pockets cannot reach the surface before the surface has cured, and they become entrapped. Hence, 3 months later the vehicle is left out in the sun … and bingo! The air bubbles expand from the heat, the paint softens and out comes the entrapped air …. creating more pinholes.
