It’s one thing to assemble an engine, plumb a chassis, even repair rusted panels. But paint is a different world altogether.
Chances are good, though, if you’re into building cars, at some point you’re going to want to tackle the paint. But painting a car isn’t something you just jump into over a weekend. A lot goes into a proper paint job, from picking the right paint (which has nothing to do with choosing a color) to making sure you don’t kill yourself in the process, and that’s not an overstatement: Modern paint is dangerous, poisonous stuff.
To get you headed in the right direction, here’s some advice we received from pros in the paint and car-building business. Once you get past this tip of the iceberg, you’ll find other ideas in the “More Resources” sidebar that’ll help you even further.
1_Ask Yourself, Why Do It?
The best way to start a do-it-yourself paint job is with the right attitude. “The major hurdle in completing your first paint job is how you approach it from a psychological standpoint,” says Dave Lane, owner of FastLane Rod Shop. (Lane has built and painted some awesome cars, including George Poteet’s green-and-flamed ’32 and a ’59 Chevy wagon that hit HOT ROD’s Top 10). “The first paint job needs to be a labor of love, or it’s probably not a good idea to try. You need to really want to do a nice job and not just look at it as a way to save some money, otherwise the quality will probably suffer.”
Art Allred from House of Kolor was more succinct: “If you are trying to save money, have a pro paint it. If you want to learn and enjoy the process, do it yourself It will be worth all the time and money you put into the project.”
2_Take Your Time
So what kind of time are we talking about here? That depends on a lot of factors: How big is the car? What kind of shape is it in to begin with? Are you changing color or respraying the same? What kind of paint will you be using? Will it be a one-color job or will it have striping and graphics? And most importantly, how good of a paint job are you after?
“The actual spraying of paint is probably about 10 percent of the job, and that’s being generous,” says Mick Jenkins of So-Cal Speed Shop. The other 90 percent is made up primarily of pre-paint prep work, followed by the sanding and buffing that’s done once the color is on.”
When So-Cal paints a ’32 roadster, for example, the entire process (for the frame, engine, body, and all the miscellaneous little parts) can take some “300 to 400 hours,” Jenkins says. Actual spraying accounts for maybe four days of that time. “We’ll have 70 hours in just color-sanding and buffing,” Jenkins says. “And that’s for a roadster, which is a small car.” Then again, So-Cal’s attention to detail is meticulous; the craftsmen there will take 80 hours to align a Deuce’s grille, hood, and cowl when assembling a Brookville steel body. “There are no short cuts,” Jenkins says.
3_When to Paint
Dave Lane and Mick Jenkins agree that there’s a definite point in a rod buildup where you want to stop building and start painting. It’s the stage Jenkins calls the “total dry build”: The car is completely assembled except for the wiring, glass, and interior. “At that point you know everything fits and will go back together,” Lane says. Adds Jenkins, “You want to make sure you won’t have to drill any more holes in the fresh paint, or adjust doors to get them to fit, bits like that.”
If you wait to paint until after the wiring is done and the upholstery is in, you’re making more work for yourself, Jenkins says, because you’ll have to mask it all off Once you’re satisfied with the assembly fit, you should disassemble the car to prime the metal, bolt it back together to do the initial bodywork and block-sanding, and then take it apart once again for the final painting, recommends Lane.
“Painting a car piece by piece will give you much more time to sand and buff the finish,” Lane says. There’s an optimum time to sand in the paint’s curing cycle. That timeframe differs depending on if you’re using a single-stage or basecoat/clearcoat system, but the basic rule of thumb is the same: Sand too soon and you can mar the finish, wait too long, and “you might as well be sanding concrete,” Jenkins says. So painting in pieces is the preferred way to go.
4_It’s All in the Prep
Proper prep is the single most important element in a high-quality paint job, including removing old paint, body filler, and rust to properly adding patch panels, aligning doors and hoods, and adequately masking what you don’t want painted.
Taking the car down to bare metal is the best way to start the paint job, so you’ll know exactly what condition the metal is in. Don’t trust someone else’s primer job, as that seemingly ready-to-paint surface could be hiding all sorts of rot and bad bodywork.
There are several ways to remove paint from a car, from media blasting to chemical stripping. Each has its merits and downsides, and the process you use depends largely on the kind of car you’re painting and what options are available to you. Jenkins does not recommend media blasting for late-model cars, for example, as the thinner-gauge metal can easily warp.
After stripping, make sure the metal is completely free of whatever media was used to remove the old paint and clean the surface. “We degrease a car at least three times before we paint,” Jenkins says. “If there is any residue on the surface, the paint won’t stick.” Or you’ll find ugly blotches in the paint, called fisheyes, caused by the paint reacting to contaminants on the metal. Take particular care when cleaning any grooves or edges in the body, says Jenkins, as residue likes to collect in these places.
“Something as simple as not mixing Bondo properly will ruin a paint job,” Jenkins tells us. If the filler and catalyst aren’t mixed thoroughly, the paste won’t cure as it’s supposed to, and there may be a soft spot in the filler. That soft spot will then ruin all the work that’s done on top of it.
5_Choosing the Right Paint
There are several different types of paint to choose from and different application methods to put them on the car. Some paints are easier for novice painters to use than others, and some paints may be illegal in your area.
Japanese varnish was the first paint used on automobiles at the turn of the century (the 20th century, that is), but it was soon replaced by nitrocellulose lacquer, and later acrylic lacquer. Enamel eventually became the automotive paint of choice, as its resin-based makeup proved more durable than lacquer, and it cured to a high gloss without needing to be polished. Modern automotive paint is made from acrylic urethane, with durability properties that allow it to withstand acid rain and other contemporary airborne hazards.
Lacquers are still available for those who want an era-correct paint, and many of our experts agrees that lacquer is probably the easiest paint to work with of those currently available. But no one recommends its use. Lacquer is solvent based, and it dries as the solvent evaporates. That process causes the paint to shrink over time, “and it will continue to shrink and crack from the time you spray it until the time you sand it off and repaint,” says House of Kolor’s Allred.
Lacquer’s chemical formula also makes it illegal to use in certain areas that are sensitive to environmental toxins. Ironically, urethanes are legal to spray even in eco-sensitive areas, although they are “bloody lethal,” as Mick Jenkins puts it, if used improperly. As you might guess, their use is strictly regulated in these “compliant” areas. (More on that topic later.)
For the novice painter, all our experts agreed that it’s best to avoid kandies, mica, pearl, or other special effects that complicate the application process. The easiest to apply is single-stage paint, meaning the topcoat is paint with pigment and chemistry to enhance its durability and gloss.
More common these days, especially among factory paint jobs, is two-stage paint. This basecoat/clearcoat process entails laying down pigmented paint (the basecoat) followed by a non-pigmented paint (the clear). The advantage to the two-stage process is a finish with a deep look to it; the disadvantage is that “you have to paint the car twice, don’t you?” says Mick Jenkins.
Why not use the specialty paints, like micas and pearls? They contain compounds–the pearlescent and reflective flakes–suspended in the paint that need to be maintained at a consistent concentration so that all the paint that comes Out of the gun matches. If you don’t maintain the proper formula between shooting the hood and the doors, for example, the panels won’t match. Or if you overlap coats inconsistently as they come out of the gun, some areas will have a higher concentration of the pearl or flake than others.
The same is true with kandy paint, says Jenkins. Kandy’s translucent nature makes it tricky to spray without streaky results. Plus, each additional coat of kandy makes a panel darker than the one before it. “So you have to paint the car assembled or every panel will look different,” Jenkins says.
Finally, all of these special paints are extremely difficult to match or blend if scratched, since it can be difficult to replicate the concentration of special materials after the original paint job is completed. “So if you get a scratch in the door, you might have to repaint the entire side of the car, right down to the base color, to get a match,” Jenkins says.
6_Do Your Homework
As part of the paint selection process, make sure you pick up the tech sheets and material safety data sheets that go with your specific paint.
Tech sheets, also known as product information sheets, will provide information about compatible primers and sealers. Tech sheets include application instructions (recommended number of coats to cover, drying times, recommended spray gun air pressure, and so on) and the proper reducing formulas needed for various ambient conditions.
Also look for a Material Safety Data Sheet (MSDS) that lists the hazardous ingredients found in the paint, the various dangers of overexposure, first-aid and fire-fighting, and protective measures to ward off overexposure.
A MSDS sheet sounds like overkill, doesn’t it? Well, to Jenkins’ point about urethanes being “bloody lethal,” they contain isocyanates, a cyanide compound. These are poisons that attack soft tissue, which means they can cause damage to your eyes, ears, nose, throat, and respiratory system. Overexposure can even lead to brain and nervous system damage. So you need to protect yourself with some safety gear.
The old-school charcoal-canister masks don’t cut it when using urethane paints, said John Sloane of the Eastwood Company. The charcoal is designed to pull solvents out of the air, but urethanes have no solvents and the charcoal is ineffectual against isocyanates. For that you need protection on the order of a full hood and fresh-air respirator. To be truly safe you should add a protective suit and nitrile gloves.
The safety gear doesn’t come cheap. Eastwood’s Hobbyair full-face system costs more than $500, and Jenkins has seen respirators go for as much as $1,200 to $1,500. “But you’re putting on plastic,” Jenkins says, “and your body doesn’t cope well with that super-toxic material.” Many of the painters we spoke with may have been more cavalier about protection years ago, but their bodies now can’t stand any paint exposure. Jenkins, in fact, suits up just to stir a can of paint, to protect him from splashes.
8_Location, Location, Location
Speaking of staying safe, none of our experts believed that spraying a car in a garage is a good idea. For one thing, it would take a lot of work to protect other stuff in the garage from overspray damage. Overspray is a fairly benign problem compared with fire. If your garage has any sort of gas-powered appliances in it, like a water heater or clothes dryer, they would provide convenient ignition points for lingering fumes.
Painting outside is an option for some, though not necessarily a good one. Even if you live in a rural area that’s far away from neighbors or pesky zoning and air-quality laws, you have no control over the weather or any airborne contaminants that could land on your fresh paint.
Instead, our experts recommended borrowing or renting a professional paint booth.
9_ The Right Tools
If you’ve shopped for spray guns, you’ve probably run across the abbreviation HVLP. It stands for high-volume, low-pressure, and it refers to how the aerated paint leaves the spray gun.
To explain HVLP we have to use another bit of jargon: transfer efficiency. This refers to the amount of paint that leaves the gun and actually adheres to the surface being sprayed. A traditional spray gun has an Outlet pressure of between 40 and 50 psi. At that level, only about 25 to 30 percent of the paint leaving the gun is actually sticking to the metal. The rest is lost as overspray. HVLP guns were developed to reduce the amount of paint, and therefore toxic chemicals, released to the atmosphere while painting. Their outlet pressure is only between 8 and 10 psi, but their transfer efficiency is anywhere from 65 to 75 percent.
In some areas of the country, HVLP use is mandatory for its environmental friendliness, but painters in non-compliant areas have found another benefit to the HVLP gun: Less overspray means less paint wasted, which saves money. So our experts agreed that a novice painter should skip the traditional guns altogether and learn to spray with a HVLP gun. It means using spraying techniques that are different than traditional methods (the recommended 8-inch distance between gun and metal is cut by 2 to 4 inches, and the shorter distance means the gun has to be stroked back and forth faster), but a novice shouldn’t have too many habits to relearn.
If you’ve been gun shopping, you’ve also no doubt noticed that you can pay anywhere from $150 to $500 (or more) for a gun. According to Eastwood’s Sloane, the price differences are primarily because cheaper guns have composite (plastic) internal parts instead of machined brass or aluminum.
All our experts agree you should not scrimp when it comes to buying a gun. “The price of refinishing supplies is high,” says Dan Swanson of Sears. “Why cut corners and waste material with a cheap, low-quality spray gun?” Adds So-Cal’s Jenkins: “If you buy a cheap gun, you can wind up spending more money trying to fix the spraying problems than if you bought a better gun in the first place.”
Not all good guns cost a mint, though. John Sloane has high praise for Sharpe’s Cobalt gun as a “modestly priced gun that produces a really superb finish, rivaling the finish from a high-pressure gun with the HVLP low-overspray advantage.” Eastwood’s suggested retail price for the Sharpe Cobalt gun (PN 34140) is about $160.
The Cobalt gun is also gravity-fed, with its paint cup on top of the gun, which many of our experts recommend over a siphon-feed system. “Gravity feed takes advantage of the paint’s natural flow to feed the gun, which reduces the amount of energy required to spray the paint,” says Swanson.
Choose a compressor that puts out more cfm than the gun requires, because you don’t want to stop spraying in the middle of a panel to let the compressor “catch up,” says Swanson. “If you have to wait for the compressor, you won’t be able to keep all the paint on the car wetted, and you will end up with shade changes and dry spray.”
HVLP guns have specific compressor requirements, and you may find your shop compressor isn’t up to powering a HVLP gun. “You might as well disregard horsepower and look at the compressor’s cfm output,” says Sloane, “as many HVLP guns use more cfm than the older high-pressure guns.” As an example, the Sharpe Cobalt HVLP guns require 13.9 cfm at 40 to 50 psi inlet pressure (going into the gun), compared to non-HVLP Cobalt guns that require anywhere from 4 to 13.8 cfm, depending on the model.
As a general rule of thumb, the smaller, oilfree compressors won’t have the cfm output that a HVLP gun needs, so shop for a traditional, oil-lubed compressor. Either a single-stage or two-stage compressor will work for the job, though the two-stage units generally run cooler and deliver more air for the power they consume, Swanson tells us.
10_Insider Tricks & Cool Tools
You want to make sure the gun is getting clean, dry air from the compressor, as dirt or humidity in the air feed will ruin a paint job. There are a number of filters and air traps on the market that will keep your air flow clean. Air line plumbing is another important compressor-related consideration. Many professional shops use hard-line plumbing on the walls, as it alleviates the problem of air pressure drops (which starve the gun) that can occur if you’re using long lines of rubber hose. It also removes the clutter of hoses on the floor. But if you must use hose, get an inside diameter of at least 3/8 inch for lengths up to 50 feet, says Swanson, and 1/2-inch hose for lengths longer than 50 feet. Keep the hose clean on the outside as well as on the inside, says Mick Jenkins. “Wipe your hose off with a tack rag and hang it up, or dirt on the hose can drop on your fresh paint.”
We asked all our experts for some sort of cool tool or trick process to help a first-time painter get the best results. Here’s what they said:
So-Cal’s Mick Jenkins says something as simple as properly stirring your paint will have a big effect on the final paint job. “In a can of paint the pigment is at the bottom, right? Well, if it’s not properly stirred, that pigment stays at the bottom. So the paint at the top of the can is diluted, while the paint in the bottom half is concentrated. It will be darker.”
To make sure you’re getting consistent color, especially if you’re using paint from more than one can, Jenkins recommends stirring each paint can thoroughly, then mixing them all together into one container.
Jenkins’ cool tool recommendation: a test panel card. You spray your color of choice on the card, which consists of sections that are black and white, to see how many coats are necessary to fully cover the surface, no matter what color primer you’re using.
Dave Lane recommends this process to make sure panels are as perfect as they can be before laying on color: “Initially look at the large picture (like the whole side of the car) to make sure everything is lined up properly. Once this looks correct, then move on to how the reflections are going to flow across the side of the body – through the doors and onto the fenders, Block-sand the body with the doors and fenders on so as to have one uniform reflection across the body.” Then it’s time to “hone in on the smallest imperfections,” he says. “At this point you really need to change your frame of mind from big picture to really looking a lot closer at every panel. Keep block-sanding until everything is as perfect as you can get it. If you are wet-sanding, be sure to dry the panel before checking reflections in the lights, as the water will make a panel look much smoother and straighter than it actually is.”
Lane also suggests putting a line of masking tape on any sharp edges (from door edges to body lines) when it comes time to sand and buff There’s less paint on these areas, and taping over them will keep you from burning through what’s there. You can remove the tape at the end of the buffing process to give those places a light rub.
Lane’s cool tool: Sanding sticks, cut from paint sticks, to get into really small or tight spaces.
Art Allred from House of Kolor says a guidecoat is “one of the tools most overlooked by hobbyists.” A guidecoat is a contrasting coat of color (typically black) that’s misted over primer during the body prep process. When the body is sanded, the thickness of the guidecoat that remains will show high or low areas on the body. Guidecoat “is a preparer’s best friend,” Allred says.
Sears’ Dan Swanson calls himself “by no means an expert in auto painting,” but he’s painted “probably 60-plus cars over the last 20 years, and worked in a few body shops.” So he speaks from experience when he says that “the more skilled you are at painting cars, the better you can do with poor equipment. Therefore a novice will get better results with better equipment.”
His tool recommendation: a small regulator with an air pressure gauge that attaches directly to the spray gun. “This helps reduce fluctuations caused by the cycling on and off of the compressor and allows the painter to monitor the pressure at the spray gun. If you maintain a constant pressure and a constant spraying technique, your color will stay consistent.”