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Auto Paint Work 101 - Let It ShineWhat You Need To Be An Automotive Painter From the December, 2008 issue of Mopar Muscle By Dave Young Photography by Dave Young
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Painting your car, or having... Painting your car, or having it painted, is a rewarding experience. Many times though, the end result seems like magic when a job turns out great. Likewise, repairing a botched job can be a nightmare. Follow along as we show you what you'll need to paint a car the right way, and then you can decide if you want to tackle it yourself or leave it to the professionals. One of the biggest expenses we incur while fixing up our cars is the paint job. As the cars we love get older and older, it's just hard to find one to restore that doesn't need a significant amount of body repair. If you live in the rustbelt or certain coastal areas, your car may even need to have all or most of the sheetmetal replaced or repaired, which involves hours of labor and significant cost. While it would be nice to just drop the car off and write a check for a new paint job, the fact is most of us are on a tight budget and simply can't afford to do that. Even if we can afford to have a shop perform the work, we want to make sure the body shop we're using has all the tools and equipment to repair our car properly. The decision about whether to attempt body and paint work yourself is a tough one. If you're like us, you have more time than money, so you may be tempted to perform the bodywork on your car yourself. Be warned, however, that bodywork can be an arduous and frustrating task. Replacing sheetmetal is dirty work and involves hours of drilling, grinding, and welding . . . and that's just the beginning. After the sheetmetal repairs comes the hammer and dolly, then the body filler, then hours and hours of priming and block sanding to make the panels straight enough for paint. If you get bored easily, the repetitive process of straightening body panels can drive you crazy, but if you're patient, the actual physical process of performing bodywork isn't too tough. There is, however, a certain touch that's required to get panels super-straight. Experienced body shop personnel will tell you that you can't tell if a panel is straight by simply looking at it . . . it has to be felt. This "feel" for straightness isn't something that comes naturally to most people; it has to be learned. Some people, this author included, simply never acquire the feel that tells them a body panel is straight, so we have to leave that part of the process to a professional. But even if you can't get the panels razor-straight yourself, you can still save money by performing some of the bodywork at home. If you can drill, grind, and weld, you can replace sheetmetal panels, and roughing in the panel with filler and block sanding isn't too tough either. As for the actual paint job, however, be careful if you don't have a paint booth at your house. We have seen some great paint jobs on cars that were restored by owners in their own garages, but then we've also seen some pretty crappy ones. The outcome of a paint job is dependent on a lot of variables, so unless you're pretty comfortable performing bodywork, prepping, and painting, or don't mind spending the money and time to re-do things as you learn, you might want to leave it to a professional shop. If you really are into performing bodywork yourself and don't want to screw things up, consider taking a class at a community college or tech school to learn the basics. There are also books available that can be very instructive, but in the end, there's nothing like experience.  The first step to checking...  The first step to checking the condition of your car's sheetmetal is to strip off the paint and bodywork on top of it. While this can be performed by having the entire car media blasted or dipped in a chemical stripper, the cheapest way is to simply grind the paint and filler off the car with an electric or pneumatic grinder.  Heavy Metal If you want your...  Heavy Metal
If you want your paint job to last, the metal underneath must be free from oxidation (rust). If rust isn't completely removed and neutralized, it will reappear, chemically destroying the body filler, primer, and paint, and causing your new paint job to bubble. Any good body shop will tell you that a great paint job starts with proper metal preparation, and to properly prep the metal, you'll need the right tools.  Once stripped, there's a good...  Once stripped, there's a good chance you'll find metal that needs to be removed and replaced. An air chisel will come in handy here, as will a sawzall with a metal blade and a die-grinder with a cutoff wheel.  Most body panels are spot...  Most body panels are spot welded in place, so a spot weld cutter like this one from Blair Tools is a very useful tool. The cutter will remove the spot weld, but unlike a drill bit, it will leave the metal underneath so the new panel can be welded to it.  Fortunately, replacement panels...  Fortunately, replacement panels are available for most Mopar vehicles, but you may have to cut your patch panels from a replacement quarter-panel like we are in this photo. Again, a die grinder with a cutoff wheel works great for this job. Panels that aren't available from the aftermarket will need to be fabricated.  To hold panels in place for...  To hold panels in place for fitting and welding, it's nice to have a good set of Vise-Grip-style clamps. The bigger the repair, the more clamps you'll need.  Whether you're replacing an...  Whether you're replacing an entire panel or just putting in a patch, you'll need a welder. Sheetmetal repairs should be welded using the "stitch" method, so the heat doesn't warp the new panel.  Body panels are made from...  Body panels are made from fairly thin steel, so it doesn't take much energy to weld them. Even an inexpensive welder like this small Lincoln unit is sufficient for most bodywork you'll encounter.  If a panel is dented but not...  If a panel is dented but not rusty, it doesn't necessarily need to be replaced. There are many types of dent pullers available that can pull the metal back into shape, saving you the trouble and expense of installing a replacement panel. Whether you have the knowledge and experience to perform bodywork or you simply want to learn as you go, you'll definitely need the right tools. If you plan to have a body shop complete the work, knowing they have the proper equipment is a step in the right direction when it comes to picking a shop. The basic body shop tools are fairly minimal as you can get away with a sanding block, some sandpaper, and cheap paint, but like anything else, the sky's the limit if you want to fill your shop with specialized tools to make the job easier. The bottom line, however, is time. If you don't have the best tools, you'll spend more time to accomplish a certain task; with better tools, less time is required. Regardless of tools, however, bodywork is labor intensive, frustrating, and trying to hurry only makes it worse. So if you're going to do it yourself, you'll want to give yourself a realistic timeframe, and you'll need to invest in at least some of the equipment we'll discuss in this article.  After welding, an electric...  After welding, an electric or pneumatic grinder can be used to grind the welds flush; the metal can now be treated and is ready for filler.  Anytime a car's body is stripped...  Anytime a car's body is stripped to bare metal, the metal should be treated with OSPHO or another agent with phosphoric acid as the main ingredient. This will chemically neutralize any surface rust and etch the metal in preparation for primer and body filler.  While a little pricey for...  While a little pricey for the novice sheetmetal fabricator, an English Wheel (like this one by Sharpe)...  ...and a Power Hammer (like...  ...and a Power Hammer (like the one shown by Dake) can be used to fabricate patch panels that aren't available from the aftermarket.  Getting it StraightAfter the...  Getting it StraightAfter the new sheetmetal is bolted or welded in place, it's time to start straightening panels. This process is actually started by shaping and straightening the metal panels themselves so less filler will be needed. Then body filler can be applied and the process of filling, sanding, priming, and sanding again can begin. This procedure is repeated until the panel is straight and ready for final prep and paint.  By using a body hammer (outside)...  By using a body hammer (outside) and metal dolly (inside the quarter), minor imperfections can be removed from the metal body panels prior to adding filler. Hammer and dolly sets are available from most tool stores and are relatively inexpensive.  Applying body filler to panels...  Applying body filler to panels isn't rocket science, and the tools you'll need are as simple as a squeegee and a piece of cardboard or plastic to mix the two-part body filler on.  Once the filler has cured,...  Once the filler has cured, an air-file can be used to knock down the high spots of excess body filler. While the pneumatic file saves time, manual files (commonly known as "bondo" files) are also available to perform this task, and they're a lot cheaper.  If there's one tool you'll...  If there's one tool you'll want to purchase to help with bodywork, it's an orbital sander such as the Snap-On unit shown here. A power sander like this will save you the labor of hand-sanding body filler and primer, and the random orbital action will help keep panels straight and free from imperfections that can be caused by hand-sanding.  Eventually, the panel will...  Eventually, the panel will need to be block-sanded by hand. Be sure to use a foam sanding block for this procedure as sanding without one will leave indentions from your fingers pressing the sandpaper into the panel. Sanding blocks are cheap and available from any tool supply or home improvement store.  To get panels straight, a...  To get panels straight, a dry guidecoat should be applied. This dark colored material marks the panel, and as the panel is sanded the guidecoat remains in the low spots. The same result can be achieved by "misting" the panel with black spray paint, then sanding to reveal low spots. High spots are indicated by sanding through to bare metal.  This panel has been guidecoated...  This panel has been guidecoated and then block-sanded. The low spots are clearly indicated by the dark colored guidecoat remaining on the panel.  Straightening the panels is...  Straightening the panels is the most time consuming part of performing body work. Each panel is block-sanded, filled, sanded again, coated with guidecoat, and sanded again. The process is repeated until the panel is straight enough for final prep and paint. Prep and Paint
Once the body panels are straight, it's time to seal the body in catalyzed primer, prepare the car for paint, and finally, paint the car. Again, there are some specialized tools needed to perform these tasks: a paint gun, masking tape, and paper. A paint booth is also nice, but most of us don't have one at our home shop. While a paint booth is a great way to reduce overspray and provides a clean environment to paint in, we've also seen some nice paint jobs that were performed outside, or in improvised paint booths made from plastic sheeting and 2x4 boards. Experienced painters will tell you, however, that it's not the booth so much as the way the paint is applied that determines the quality of a paint job, and experience is the key. If you aren't sure about painting your car yourself, you can always perform the bodywork and then pay a paint shop to shoot the car.  With the panels straightened,...  With the panels straightened, it's time for a coat of sealer/primer. This two-part epoxy-based primer will be the final primer that's under the paint, and will seal the paint from the bodywork and metal underneath.  After the epoxy primer cures,...  After the epoxy primer cures, the body lines are taped off and the entire car is block-sanded once again in preparation for paint. Plan on using lots of masking tape and sandpaper.  Before paint can be applied,...  Before paint can be applied, the car will need to be taped off. We know what you're thinking, just use newspaper . . . well, the problem with newspaper is that it's porous, and the chemicals in the paint will soak through it and contaminate what's underneath. Our advice is to use the proper paper and masking tape to prevent unnecessary clean up later.  A paint booth provides a well-lighted,...  A paint booth provides a well-lighted, clean, controlled environment in which to paint the car and has a vacuum system with filters to suck overspray away from the freshly applied paint. A paint booth also has self-contained pressure regulators and water/oil separators to keep contaminants out of the paint. We highly recommend using a paint booth when painting your car, or at least build an improvised booth with boards, plastic sheeting, and fans.  Most body shops have a paint...  Most body shops have a paint mixing station in-house, allowing the painter to mix his or her own colors from a computer-generated mixing sheet. If you plan to do it yourself, a body shop or paint supply store can mix your color for you.  Mixing the color isn't the...  Mixing the color isn't the only mixing you'll have to do. Most modern paints are two or three parts, so you'll need a mixing cup, strainer, and stir sticks to mix the correct proportions of color with the reducer and hardener.  Older can style paint guns...  Older can style paint guns like the one shown above are still used to paint cars...  ...but the newer High Velocity...  ...but the newer High Velocity Low Pressure (HVLP) guns perform well and have less potential for overspray. Either way, practicing with the gun before painting the car is a good idea.  The proper safety equipment...  The proper safety equipment is mandatory when you're performing body and paint work. The chemicals in body fillers, primers, and paint can damage the skin and lungs, so don't risk your health just to make your car shiny.  Whether you decide to paint...  Whether you decide to paint your car yourself or take it to a professional, we hope you now have a better understanding of the tools, equipment, and process for performing paint and bodywork. After learning what it takes to paint a car, you might decide to have a shop complete all or part of the work for you, but remember, painting a car is like anything else-with patience and practice, you can learn to do it yourself.
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