Base Color Sanding - Part 3
Posted by Jay Schneider. Filed under Paint.
February 15, 2012
With the advent of waterborne technology, this allows us to apply thinner coats of paint – this thinner substrate if you will, makes it more critical to have a consistent grain of aggregate across the face of the sandpaper. Mylar and plastic type backings have become a very important breakthrough in this technology. The nature of these extruded films is to allow the grains of aggregate to lay down totally flat eliminating the highs and lows paper backed papers have. This elimination or minimizing of the highs and lows allows for a more consistent cut.
Speaking of aggregates, there are as many types of minerals as stars but only few make the grade for use as sandpaper aggregates. Some abrasive particles are found in earth bound forms, other are synthesizes under high heat and pressure to form them. Minerals like emery (fingernail files), garnet (balsawood airplanes), or flint (electronic contact points) are too soft to use for auto refinishing. Silicon carbide, aluminum oxide and ceramic particles are mainly used in our business.
Obviously price is also part of this equation. Labor rates are the most expensive component in our business so a paper that cuts faster, lasts longer between paper changes will quickly pay for itself. Silicon carbide is made from sand and carbon fused together in a furnace. As silicon carbide paper is used, the particles fracture into smaller particles. Problem is they fracture quite readily and don’t last very long which is why silicon carbides are mostly used in finer papers. Aluminum oxide is manmade synthetic material made from bauxite, coke and iron fused together under varying temperatures – some are heat treated others not – it all depends on the application. Ceramics offer the best of both worlds but are more expensive as well. Ceramics may contain zirconium dioxide and alumina – these two when combined produce a very hard particle which cuts quickly, lasts longer and finishes better.
Now that we have briefly covered the makeup, we’ll cover sanding techniques next…..
Keep the blue skies up and Happy Motoring!
Scott S. Mc Lain
Lake Country Mfg.