How To Repair Paint Flaws without Respraying - Part 2
In part one I explained how you can paint your car at home in your garage with decent results, but what if you got some minor dust, runs, or over-spray in the finish? Relax... you can fix that without having to repaint. More importantly, you can turn that "decent" paint job into something to be proud of.
First of all, you will want the paint to be good and dry before attempting any repairs to the finish. I recommend 24-48 hours to allow the paint to dry before wet-sanding and buffing. Sitting around waiting for paint to dry will give you the opportunity to return to your local paint supply store. You will want a sanding pad designed for wet-sanding (I use 3M part #05526), and some sandpaper made for wet-sanding. The wet-sanding paper you will want should be a minimum of 1,000 grit, but also buy some 1,500 grit. Some people take it a step further and use 2,000 grit or even finer (higher numbers equal finer grit), but I find you can get amazing results with 1,500 grit sanding. You may think the word "grit" is misleading because of how fine these papers are, but make no mistake; they will sand the paint surface. Also on your shopping list will be an electric buffer, preferably variable speed, and not a polisher ï¿½ there is a difference. A polisher is typically used for the application of wax and polish, where a buffer is for rubbing compounds as well as polishing.
I use an assortment of rubbing compounds, but a medium cut and fine cut compound, followed by a finishing polish should suffice. Rubbing compounds and finishing polish require different pads on the buffer. Asking at your local paint store will get you the right pads and compounds for the job. Personally I use 3M compounds and polish, finishing up with a 3M product called Final Inspection. This is a spray-on, wipe-off application that will remove the haze left over from buffing. If you're buying a different brand, ask for similar products in whatever brand they sell at your local paint supply store.
Starting with the 1,000 grit wet-sandpaper, on your hand-sanding pad, you'll want to begin with the roughest areas on the paint first (the areas with the worst flaws). Have a small pail of water with you and keep the sandpaper wet by dipping it often into the water. Some people prefer a spray bottle or a hose trickling, but whichever method you choose, the important thing is to keep the surface and the sandpaper wet.
Once you've sanded out the larger imperfections with the 1,000 grit paper, and have it smooth, go over the whole car with 1,500 grit paper. This method will remove minor dust, many runs, and even orange peel. Sand in a different direction each time you change grits. This will eliminate sanding scratches left from the 1,000 grit paper. For those of you who may not be familiar with the term "orange peel", it refers to the bumpy texture of the paint. It has nothing to do with the color orange. If you examine the surface of an orange, you will see small bumps or dimples in the surface. Paint often has a similar finish, thus the name.
If you lightly wet-sand an area of your paint and dry it off, you will notice light and dark spots. This is because you're sanding down the high points of the orange peel bumps. Once you've finished sanding, the surface should be completely smooth. You're actually sanding off some of the clear coat, which is why you applied those extra coats of clear when you painted. It's vital not to sand too far, and use extra caution near the edges, corners, and bodylines.
Now back to the rest of the car
Now that the car has been wet-sanded with the 1,500 grit wet paper, you'll notice that there is no shine to the paint. This is normal, and usually the point where most people think they have to spray on more clear. I wouldn't do that to you. Let me explain how to get that shine back, better than ever. Wet-sanding a whole car is a time consuming process but the end result is well worth it. Once the whole car has been sanded and dried off, you are ready to buff it. Perhaps I should say it's ready to be buffed. Whether or not you are ready to buff it remains to be seen. Buffing a car with new paint is trickier than it looks, especially if you've never done it before. If you have access to an old car or body panel (like a hood), I suggest practicing on that first. Fresh paint is a lot easier to damage with a buffer than cured paint.
Some people prefer to apply compound directly to the buffing pad, where others prefer to apply it to the car itself. There is no right or wrong in this, it's simply a matter of preference. I apply it to the car and spread it around with my hand, then buff. I find this creates less chance of compound getting flung around as the buffer spins. Either way you apply the compound, work in small areas, like two feet by two feet or so. Working in a larger area increases the chance of the compound drying, which makes it considerably harder to buff off. Also do not work in direct sunlight. You can do your wet-sanding outside in the driveway, but bring the car back into the shade of the garage when you buff, or wait until there is shade in the driveway if you want to do it outside where the light is probably better.
I suggest three applications of each compound, starting the buffing process with the medium cut compound, and then fine cut. Do the whole car once (or at least the whole panel), and then give it a second pass, and a third. You will start to see the shine come back from the first pass with the medium cut compound but we're going for mirror finish here, not just sort of shiny. Friction creates heat which will damage the paint, so keep the buffer moving and don't apply much pressure at all. Let the machine do the work! I hope you beginners practiced on an old hood like I suggested.
After you have finished with the rubbing compounds, switch pads and use the finishing polish. Again I suggest three applications of this. You will notice the car is covered in a haze at this point, which is where the Final Inspection spray comes in. You've made the paint shine by buffing it, now clean it with the Final Inspection spray and wipe it off. Often once is enough, but if there is any remaining haze, go over it again with Final Inspection.
Now you have a very shiny car that you can tell everyone you did yourself. If you're thinking a good coat of wax will make it perfect, you couldn't be more wrong. Paint manufacturers generally agree that you should avoid waxes for at least 30 days. Wax will seal the paint so that potentially harmful contaminants can't get in, but they also prevent the solvents in the paint from evaporating, which they need to do. You can wax your car if you like, but wait at least a month before doing it, or you will ruin the new paint. Other things to avoid in the paint's first month are car washes and pressure washers. Car washes have brushes that can damage new paint. Even touchless car washes use water under considerable pressure, just like a pressure washer. It should be obvious that blasting water or anything under pressure at new paint can't be good for it. To wash your car, I suggest a garden hose with only gentle pressure, a soft cloth designed for washing cars, or a sponge, or car wash mitt, and car wash soap.
See you at the car show!