If the 1986 Dodge featured in last month's article "Mail-Order Pride" about how to spray Auto-Air Colors water-based paint over Summit Racing's high-solids urethane clear has served to do anything, it's been a great test bed to prove long-term product durability. From the very start, using Summit Racing DTM epoxy primer over bare metal to the final stages of color sanding and rubbing its five years of exposure to the elements have not caused a failure. No rust or shrinkage caused by the primer, and no dulling back of the clearcoat from exposure to UV rays or color sanding.
It was last May 2013 that I returned to cover the autobody students at Riverside City College color-sanding and rubbing out the Dodge's second stage clear topcoat. At the end of the school day I loaded the old Ram on my car trailer and hauled it home. As with any vehicle that's been apart too long there was list of vital parts missing from the truck. I lost interest and parked the Dodge in my driveway and forgot about it. The cats used it as a springboard to jump from the roof of my house and the neighbor's gardeners liked it for hurtling rocks from the jet stream of their leaf blowers. Then one morning I was in the mood to dig back into the Dodge project.
There's more than one reason to color-sand and rub out a paintjob. The first is color sanding is the final step toward smoothing the surface as flat as possible and catches any dust particles that might have settled in the clear before it dried thoroughly. The end results are the finish has been made to appear as flawless as possible.
The second reason one would want to color-sand and rub out a finish is because this process can be an absolute savior for any paintjob that didn't turn out as well as expected. There's an old adage amongst painters that if you don't get any runs you're not trying hard enough. That's hard enough as in trying to "slick it," a term meaning a painter did a perfect job of laying the paint on to look as slick as glass. Performing such a feat is every painter's ultimate goal, but there's going to be some beginner's dues to pay along the way. These dues will come in the form of runs, fish eyes, dirt in the paint, and most likely some paint flaws that no one has ever seen before. No matter what the flaw or blemish might be, color sanding, followed by a thorough polishing (rub out), can save the day.
The third motivation for color sanding and rubbing is to revitalize a paintjob that for any number of reasons has lost the appearance of new paint. It's only a matter of time for an automotive finish to lose its glossy sheen due to the effects of ultraviolet light, extreme heat or cold, or even the quality of the paint that was used. Typically a color-sanded and rubbed paintjob using lower-quality paints is more subject to a condition that's known as dull back. In some cases, it takes only a few months before the shines goes flat, and if left unchecked, the finish can deteriorate to the point of flaking and peeling. If caught in time, the ill effects of allowing a finish to deteriorate can be delayed or avoided all together.
There is an expression used by painters that's known as breaking the skin. There was a time when any paint that was color-sanded and rubbed wouldn't hold up as well as paint that was allowed to keep its skin. In the 21st century's second decade, the advent of superior-quality, high-solid paints means a color-sanded and rubbed finish can endure as long as an untouched finish. That's great news for DIY guys and professionals alike because show-quality results are now easier to obtain and will endure for a long time.