Taking on your first paint job as a DIY auto enthusiast is an intimidating ordeal. While it doesn't seem as physically demanding as an engine swap or differential rebuild, it is rather complicated. There are a lot of steps to take, all of which are as important as the paint itself.
You've heard the phrase "it's all in the prep work" whenever a paint job is complimented, and that's the truth. While the painting itself is important, everything you do up until then will define the end results. In fact, you'll spend far more time actually prepping a car than you will painting it.
It's a long, arduous journey, so getting your head in the game well beforehand is advised. Don't let it intimidate you, though. Embrace it! This is the point where maintenance or upgrades become an art form. And once we're through going over the basics, you can get to having some serious fun making your car shine to your heart's content.
What do I need in my tool box?
As with any kind of project, your mind goes right to the tools you'll need to get it done. After all, the cost/feasibility of that part of the job will largely determine if it's something you'll attempt in the first place.
Starting with the painting itself, you'll need an air compressor, air lines, water filters, a pressure regulator, and the paint gun. You'll also need plenty of mixing and measuring cups to get the paint just right. Of course, a respirator and a paint suit are important investments too.
Prepping a car for paint is a nuanced task, as the condition of the project largely determines what you'll need. In any case, “smoothing things over” is the name of the game. As such, you'll want an electric palm sander, a sanding block, and lots of sandpaper. Of course, some body filler and acetone are always going to come in handy too. Additionally, a die grinder, an angle grinder, and a surface tool can really speed things up with the proper attachments.
If you're among the lucky few, you won't need to worry about sheet metal. The rest of us in the real world, however, will need to handle some metalwork. At the very least, dent removal can be tackled with some type of dedicated specialty kit. For more serious jobs, you'll need to get yourself set up with a hammer and dolly set to really work metal over. Those of you battling rust will need to invest in a wire welder. MIG or flux will work for sticking full replacement panels or small patches in place.
Where do I start?
The work isn't always going to look the same, and your exact approach is going to depend on the condition of the application and the scope of the project.
As for the majority of the car, you don't necessarily need to strip it all down to the bare metal. Just getting all of the paint off but leaving the factory primer should be fine, unless you have a specialty undercoating you prefer to use. That's not to say you can't layer primers, though.
Starting on blemishes is a bit different, as you really do want to get down to bare metal. Unless you're working with surface rust or small dents, you don't know what the paint is hiding. Once you're down to the metal, you can get a better look at what's going on and determine the best approach for repairing the area. Whether that means patching it, filling it, or working it flat really depends on the exact spot you're working on.
Masking vs Disassembly
If you're painting a car from top to bottom, and not just a small section, it's beneficial to disassemble the car. Door jams, hoods, trunk lids, and even window channels are all areas where paint hides, and if you don't address them, your paint simply won't match.
In extreme cases, that means exposed metal in these areas won't be protected by paint, leading to rust issues that will eventually make themselves known in a grand fashion. Yes, those of you matching the new paint to the old are okay to leave the panels in place, as long as the paint in those hidden areas is in acceptable condition.
Disassembling the car looks different in different situations, though.
Luckily, many cars have black engine bays and undercarriages. The paint doesn't extend into the cabin or trunk floors either. That means, you don't need to gut the interior or pull the driveline unless you're tackling a full-on restoration or custom job.
In most cases, you just need to remove the doors, hood, trunk, and any trim or miscellaneous components you don't want to paint. But remember that those parts may also need to be broken down further.
Removing interior parts, glass, and seals on the exterior is critical to doing the job right. Removing the front and rear glass from the car itself is necessary if you need to paint the window channels in which they sit. After that, you will need to spend more time masking whatever you don't want to get paint on as well.
What’s the deal with sanding?
No matter the job, sanding is a big part of it. At the very least, you need to scuff the surface to give the primer something to bite into. Sanding will also help produce even surfaces throughout the car. If you're leaving any base coats on the car or using body filler, you can expect to spend a lot of time working those areas down to sit level with the rest of the car. Feathering the edges is then used to help smooth out any harsh transitions.
Any small blemishes, no matter how tiny, will show up in the layers on top of it. Filling and sanding is how you keep them from ruining an otherwise perfect paint job. Considering how much work and money you can invest into this, it's worth going all-out in the sanding process to produce the best results possible.
Will any paint do?
The last stop and first stop on this journey is the paint. What paint you use is just as important as all of the work you do before laying it.
Different applications use different paint. Older cars have single-stage paints; newer cars feature paints that rely on clear coats. Sometimes, different panels might have different types of paint as well, and let's not forget the many custom colors on the market.
If you're doing custom work and aren't using factory or even period-correct paint, you're in for more homework. What you choose to use ultimately depends on your preferences. Just keep an eye on quality.
The rest of us have the benefit of using factory paints. Even if you're working with an older application or want to save some money, you can find reproduction paints that simplify this process. Again, you need to keep an eye on quality, and especially the colors. Sometimes the hues aren't quite perfect, and that's something you want to really read into. Otherwise, you'll have a car that just doesn't look quite right. It might not bother anyone else, but it will really eat away at you.
As for single-stage or clear coat, that's either up to you or the car. Most modern cars use a more durable, smoother-looking clear coat base coat system. Older cars, however, use single-stage paint. What one you use really depends on your preferences, project demands, and overall budget.