The secret to a show-winning finish, once the endless repair, de-rusting, block-sanding, and painting are done, is color-sanding. Experience can teach you to shoot paint well enough that most people would be pleased with the job, but no painter, no matter how experienced or talented, can shoot one of those perfect mirror finishes so deep that you worry you might fall into it. I'm talking about the kind of quality work you see at shows. To obtain that level of perfection, you need to do a few more hours of work -- quite a few more hours in fact.
Painters used to call the procedure rubbing out; it was performed with compounds and pastes that came in cans. The upgrade on painted surfaces worked reasonably well, but the compounds simply rounded off paint imperfections instead of eliminating them, and the process removed a significant amount of paint as a result. Now, thanks to microfine sandpaper that comes in No. 1,000-, 1,500-, and 2,000-grit ranges, a new finish can be made flawless.
Once a truck is color-sanded, there's also a newer, simpler polishing process called System One, invented by Tom Horvath. Tom's also the co-author of the latest book, Pro Paint & Body, published by HP Books. The new system makes the final polishing and buffing much easier, and it only uses one compound to produce a finish second to none. More on that subject later. Here's how to color-sand correctly.
To begin, put a drop or two of dishwashing liquid in a clean bucket and fill it with clean water. Next, tear three or four pieces of the 1,000-grit microfine sandpaper in half and place them in the bucket also. Leave them in the bucket of water for about 20 minutes to soften their edges.
While you're waiting for the paper to soften, wash your truck completely to remove any grit or dust, then gently dry it with clean terry cloth towels. Next, take a tack rag and wipe over the truck's surfaces one final time to make sure the paint is absolutely clean. A small particle of grit can make deep scratches in even the hardest finish. If you're working outdoors, wet down the surrounding area to keep dust under control, and keep a garden hose running with a trickle of water on the surface at all times.
Wrap a piece of the softened 1,000-grit sandpaper around a thin, rubber sanding block if you're going to be working broad, flat surfaces. Otherwise, you can just fold the sandpaper in thirds. Keep wetting the surface of the vehicle in the area where you're sanding and keep it wet while you work. Place your hand flat on the paper at all times and start sanding in short, criss-cross strokes. Avoid applying excessive pressure and never sand with just your fingertips -- you'll create grooves if you do.
Only move the sandpaper about 4 inches back and forth. If you do make a scratch, it will be a short one and easier to buff out. Using shorter, quicker strokes requires about the same amount of time as the longer sweeps most people are used to. Besides, you shouldn't worry about time when color-sanding. If you are not a patient person, you should give this task to someone who is.
A clean rubber squeegee or rubber block is the best tool for checking your progress. Swipe the squeegee across the sanded surface periodically to clear it of water. Only when you have the surface completely free of any suggestion of orange peel or imperfections are you ready for the next step.
Proceed to the 1,500-grit sandpaper and repeat the process until all the coarser scratches are eliminated. Finish with the 2,000-grit paper in order to remove all of the fine scratches. Only when the paint has a consistent, smooth, satin finish can you continue to the buffing stage, if you want a show-winning finish.
For the next step, you'll need an oscillating buffer. Today's two-pot paints are rather hard to rub out by hand. The buffer we prefer is a variable speed DeWalt, but the buffer you choose is less important than how you use it. These are heavy-duty tools that require a little hands-on experience to get the hang of them. To prevent ruining an expensive paintjob, learn on your beater first.
Never buff sharp edges or crowns, because you can remove the color topcoat quickly if you aren't careful. Paint tends to build up in valleys but is blown away from edges during spraying, so it can be very thin in those places.
Always work in a well-lighted area. It is important to be able to study a vehicle's finish from a number of angles and that takes good, even lighting. Dark-colored trucks can be a special challenge. And if you are building a show truck, you will want to make sure to inspect it under the kind of lighting in which it will be shown, whether it will be outdoors or indoors, under fluorescent lights that will show every imperfection.
Before buffing any vehicle, wash it carefully using a mild solution, such as Maguire's Car Wash, and clean water, then dry with a chamois. Grit or dirt will wreak havoc with your truck's finish if it gets under a buffing or polishing pad. For safety, you may want to use a tack rag again to be sure the paint surface is free from dust or dirt. Removing grit scratches will thin the protective quality of your paint. It's a good idea to tape over drip moldings and sharp edges, and mask windshields and windows to keep polish splatter off.
Start using the No. 1 sheepskin pad on the buffer. Apply a small amount of System One compound to the surface or the pad. This product goes a long way. If your buffer is throwing polish, you're using too much compound. Also, place the buffer on the spot of compound so it spins it into the pad rather than out of it.
Set the buffer on a slow speed and slightly tilt it toward the working surface -- this will become easier as experience grows. Work only a surface area of about 4 square feet. Only use the 12, 9, or 3 o'clock positions on the pad to do the work. Also, tilt your buffer away from the sharp edges along doors and hoods rather than onto them, which will remove as little paint as possible.
Because you don't normally moisten the pad with water before using System One, as opposed to other polishes, never let the buffing pad go completely dry. Dry buffing describes the condition when there is no polish on the surface or on the pad. This condition will burn a painted surface and can be a very expensive mistake. Also, keep the buffer moving across the finish to avoid excessive heat buildup and don't apply too much pressure. Simply let the buffer and the compound do the work.
Never flat buff (full-pad contact) because you may lose control of the buffer. As you begin to buff a surface, you'll discover it comes to a beautiful polished shine in a very short time. If you've buffed before, you'll be surprised at how quickly the System One polish works compared to other compounds. This is because it's made with fine aluminum oxide rather than diatomaceous earth, as with most cutting compounds.
Be critical of the entire area you're polishing -- look for very fine straight-line scratches and continue to buff until you no longer see them. You'll wind up with a highly polished surface, but upon closer inspection, you'll still be able to see a very slight scratch pattern left by the pad and the polish. These very fine scratches are about a 7,000-grit spiderwebbing. Change to the special foam pad No. 2 and again apply a small amount of polish to the surface. Continue in a 4-square-foot area as before. Again, you'll develop a tremendous shine that looks dazzling. We're not quite there yet.
As you work, continue to look for scratches. At this point, they're going to be extremely fine, but if you see some coarser straight-line scratches that you missed with the original buffing pad, change back to the sheep skin No. 1 pad and take them out before going on. Just remember that the more you buff with the cutting pad, the more paint you take off. Finish buffing with the No. 3 fine, sponge buffer pad.
At this point, you'll be looking at a beautiful finish with little residue or haze on the surface, because you have not yet dry buffed using a microfine cloth. This residue will remove quickly and easily, but don't be tempted to touch this surface with an ordinary towel -- scratches may occur if you do.
Finally, apply a carnauba wax with no cleaners and rub it gently. Don't continue to apply wax in order to build it up. The heavier the wax is applied, the more pressure is needed to remove it, thus causing more scratches. The only reason a heavy wax is needed is to cover up errors. And if there are still fine scratches in the surface, they should be dealt with in the proper way -- by additional polishing. Otherwise, you will simply be masking the problem.