|
|
Paint Cut And Polish Guide - Smooth As GlassGiving Your Corvette Paint The Final Cut And Polish From the July, 2010 issue of Corvette Fever By Steve Dulcich Photography by Steve Dulcich
|
|
This '62 Corvette has been... This '62 Corvette has been meticulously repainted in a custom tangerine candy color by Brian at Corvettes and Customs, in Upland, California. The final touch will be a cut and polish job to make it flawless. For the average paint job, the work is done once the paint guns are put away in the booth and the masking tape is pulled off. In the world of custom or show-quality paint, there is still work to do if the goal is to approach perfection. No matter how clean the paint booth might be, and no matter how skillfully the paint is sprayed, there will be flaws. If everything was done to top shelf standards, the texture will be minimal, and the paint surface will have very little contamination, but a glass-smooth surface with a mirror finish demands just that little bit more. Here's where the cutting and buffing step comes into play. The technique is really not new. In fact, it's a form of burnishing and polishing, which has been around for centuries. What it consists of is fine-sanding the surface until it's perfectly smooth, and then using buffing techniques to polish the paint to a brilliant luster. In the world of automotive refinishing, there are special tools, techniques, and materials designed just for this purpose. A proper cut and polish job is always a part of a custom show-quality paint job. The equipment and materials... The equipment and materials used for cutting and polishing are unique to the job, and most technicians have their own favored variations on exact materials and tools. The basics are a paint buffer, cutting and polishing pads, cutting and polishing compounds, and very fine sandpaper, from 1200-3000 grit, depending upon the specifics of the job. Technicians have their own favored materials and techniques, but the basic process is well established, beginning with sanding the surface. This is normally a wet-sanding process, using water to clean and lubricate the surface while it's sanded smooth. Wet-sanding is done with very fine sandpaper, with the goal of flattening the surface while removing a minimum of material. A break through the clearcoat can be disastrous while sanding, necessitating starting over and repainting the surface to repair the damage. Properly wet-sanding requires plenty of skill. Once the sanding process is complete, the job is completed by polishing to bring the surface to a beautiful shine. Usually this is done in two steps, with a coarser cutting step to remove the sanding scratches and quickly bring the surface to a shine, followed by a polishing step to take the surface to perfection. We recently visited Corvettes and Customs in Upland, California, where Brian broke out the supplies to demonstrate how a cut and polish is done. Our subject is Rick Stoner's '62, which was recently painted by Corvettes and Customs in a House of Kolor candy.
| Difficulty Index - 3 Wrenches |
| Anyone’s Project: no tools required | 1 Wrench |
| Beginner: basic tools | 2 Wrenches |
| Experienced: special tools | 3 Wrenches |
| Accomplished: special tools and outside help | 4 Wrenches |
| Professionals Only: send this work out | 5 Wrenches |  A timesaver that has become...  A timesaver that has become popular in recent years is an orbital air sander, which Brian will sometimes use instead of all hand-sanding. In the right hands, this tool produces excellent results, though beginners may be better off sticking to hand sanding pads.  The orbital air sander comes...  The orbital air sander comes with an extra-flexible backing pad, and is equipped to accept a hook and loop (Velcro) sandpaper retention system. The special fine-sanding sheets are available from 3M.  Step one is to sand the paint...  Step one is to sand the paint finish. This will cut any nubs, minor flaws, or fine orange peel from the surface, leaving it glass smooth. Brian uses a wet process, favoring a spray bottle for minimal mess.  While the surface is wet,...  While the surface is wet, it's difficult to see if the surface has been sufficiently sanded. Brian uses a squeegee to give the surface a quick wipe dry to check the progress. The goal of the sanding process is a flat surface with no visible gloss. He will generally take the surface to 80-90 percent flat with the power sander.  Brian finishes the sanding...  Brian finishes the sanding process by hand, using a flexible foam and rubber hand backing pad. Again, this is a wet-sanding, so the water bottle is used while sanding. Brian will take the surface of the paint the rest of the way to 100 percent flat with no shiny spots by hand.  Here's the finished result,...  Here's the finished result, as illustrated by the center portion of the '62's nose. Note that the paint is sanded perfectly smooth, with no sheen visible. Any shiny spots would be flaws requiring more sanding. When the paint is as nicely applied as that of this Corvette, it really does not take much sanding to get there.  Next, we move on to the buffer,...  Next, we move on to the buffer, which will take the flattened paint to a mirror-like shine. Paint buffers look like a sander or grinder, but turn much lower rpm, generally between 1800-2600, depending upon the specific machine. Here a wool "cutting" pad has been fitted for the first step. The pad is cleaned by "spurring" while it's spinning.  Buffing is usually done in...  Buffing is usually done in two steps, a coarser "cutting" step, followed by the fine polishing or "glazing." For the first step, Brian used 3M Rubbing Compound, No. 05974. Brian prefers to apply the compound with a brush, pre-spreading it over the area to minimize compound flinging mess with the buffer.  With a few passes at light...  With a few passes at light pressure, the finely-sanded surface quickly regains its shine. The trick is to keep the buffer moving in a back and forth pattern until the compound is buffed off.  For the polishing step, the...  For the polishing step, the wool cutting pad is replaced on the buffer for a fine-polishing foam pad. The technique for the polishing step is similar to that of the cutting step.  After compounding, the surface...  After compounding, the surface shows a good shine, but there is more to go. The finish polish or glaze will remove any buffer swirl marks and bring up a brilliant luster. Brian again uses 3M brand polish, No. 06068.  It's important to be aware...  It's important to be aware of the buffer rotation, and to avoid running the pad into an edge where it can catch and burn the paint. The correct technique is to always have the pad spin off the edge when working these areas.  There's nothing more satisfying...  There's nothing more satisfying than a freshly painted and polished Corvette, ready for assembly. This car will be a showpiece when completed, and the outstanding paintwork will separate it from the crowd.
|
|
|