Muscle Mustangs & Fast FordsHow To Paint Body
Paint & Body 101: How to Get Great Paint
Getting show-quality paint is the stuff of art and science. Not many of us know exactly how to get it, and even fewer have the patience to achieve it. Scott Brideau of Car Concepts in Nampa, Idaho, has been building, massaging, and painting automobiles since he was in his teens in his native Minnesota. He learned the ropes via experience—learning what works and what doesn’t. Brideau has built dozens of show cars in his decades in this business. This is a man who lovingly massages car and truck bodies, enjoying every minute of it, which makes him a natural for the business he is in.
Getting a great paint job isn’t cheap, quick, or easy. Brideau practices his talents in a shop in the middle of rich Idaho farmland known more for famous potatoes than exotic automobile restorations. It is here he handcrafts rolling works of art from raw steel. You can see it in his hands, which have been massaging car bodies for decades.
Brideau says that the devil is in the details when it comes to achieving a show-car finish. Step one is to assess the vehicle and make a plan. Just like when building a house, a solid foundation is the starting point of any great paint job. Brideau says a solid foundation entails proper rust repair and metal work that allows all the gaps to be correct and the panels to be in perfect alignment. He says he will spend many hours shuffling sheetmetal around and doing minor adjustments to make the gaps as uniform as possible. Once this is complete, he adds or removes metal as necessary. This is very important early in the process because it will be more difficult to make any corrections once bodywork has started. Most paint jobs begin with paint removal. There are several ways to remove old paint. Sanding with an orbital sander is known as mechanical removal and is performed with 80-grit paper. You may also blast old paint media with plastic, walnut shells, or crushed glass. Baking soda may also be used, but Brideau cautions that the surfaces must be neutralized for proper paint adhesion. In some areas there is even dry ice blasting. There is also chemical removal, which requires extensive cleanup and purification of the steel when stripping is complete.
Brideau’s preferred method is to send a car out for media blasting to remove multiple paint jobs and expose the extent of any previous repairs. On this Mustang GT convertible, which belongs to Bruce Couture of Modern Driveline, the car was still in factory paint. Brideau is comfortable with cleaning and sanding a known surface because it is an excellent foundation for new paint.
1. Prepping the original factory paint on the Fox-body convertible.
2. A couple of areas on Bruce Couture’s Mustang GT convertible had paint touchup work. On these areas, Scott Brideau chose to sand off the secondary paint so he would have a surface he could trust.
3. Sheetmetal/structural repair should be performed while the repair area is void of paint. Don’t be afraid to correct factory flaws in order to improve gaps. Brideau massages steel as a matter of practice to get gaps just right. Here, he actually broke welds to improve decklid gaps. The 1983-1993 Mustang convertibles suffer from a lot of build flaws because they were completed by an outside contractor. You will find that no two are the same. Be prepared to go the extra mile on sheetmetal work.
4. A bodyman must also be the structural technician, performing tasks such as drilling out spot welds, removing rust, and reworking/adjusting metal to improve fit. Brideau and his team do it all, from fabrication work to repairing to replacing. The Eastwood Company offers virtually everything you will need to rework steel and lay down a finish. Harbor Freight Tools is another excellent source for bodywork tools.
5. Think there is little you can do about poor body gaps? Brideau reworked this seam and reset the decklid. The result is a perfect gap, which would not have been possible without separating the seam and rewelding.
6. In this situation, Brideau was able to use a body filler spreader to check the body gap. Different vehicles have different gap requirements, which means improvised tools can be used as well as body gap gauges.
Defining Great Prep
Show-quality paint jobs begin with a plan, then meticulous preparation. Cut corners and you risk poor results. Although every professional has his own regimen, Scott Brideau tells us there are only a few proper approaches to good paint. He has plenty of experience with different methods and materials.
This is where the science comes in. With all the metal work complete, it’s time to prepare for bodywork. Although body filler can be applied to clean, sanded bare metal, Brideau prefers to seal the bare metal first with epoxy primer for corrosion protection and adhesion. For this protection, he uses Southern Polyurethanes (SPI) epoxy primer. He will sand the bare metal to a uniform finish using fresh 80-grit sandpaper on a dual-action sander, then spot-sandblast any pitted areas or corners that the sander could not reach.
Next, every square inch gets a thorough cleaning with a waterborne wax and grease remover. This cleaning is done multiple times to thoroughly clean the metal’s pores, then the car is allowed to dry completely before epoxy primer is applied. This phase of prep is extremely important and should not be circumvented because the durability of all of your body and paint work depends on it.
Even though this convertible was not stripped to bare metal, it received the same treatment once the original factory paint had been sanded. After the epoxy sealer is applied, it needs to be allowed to cure overnight. After curing, and depending upon the condition of the vehicle, Brideau may choose to spray the entire car with three coats of Feather Fil polyester primer. Whether you choose this technique or choose to apply body filler directly to the sealer, either can be applied onto the epoxy without sanding it first for up to three days from the time the epoxy was first applied.
Next, the epoxy is thoroughly sanded and cleaned before the application of any other materials. The epoxy is considered “open” for these three days, which means materials can adhere to it without additional preparation. Once the coat of polyester primer has cured, Brideau sprays the panels with a guide coat and begin initial block sanding with 80-grit paper. This quickly reveals high and low spots in the panels and helps cut the panels straight. Low spots are identified by the guide coat that remains. At this point, Brideau outlines these areas with a pencil, sands the low areas for adhesion, and applies body filler to them. After the body filler cures, he continues blocking.
The guide coat process continues until all the high and low areas have been resolved. Depending on how much material has been removed, another round of polyester primer may be required. Once the body panels are straight and are sanded with 180-grit paper, two wet coats of the epoxy primer are applied, allowing 60 minutes between coats. Brideau lets the epoxy cure for two days, then blocks it out with 400-grit wet/dry sandpaper. He likes to use different shades of epoxy at this point to help him see how much epoxy remains while sanding. The epoxy coat will produce an excellent base for a final coat of epoxy sealer and paint.
7. Scott Brideau uses Evercoat Feather Fill Next Generation G2 No. 100713 gray polyester filler primer, following the instructions closely. This is a great professional-grade poly primer.
8. This is SPI epoxy and activator. Brideau likes to use a mixing lid for ease of stirring and dispensing the exact amount of epoxy he needs.
9. With the polyester primer fully cured, Brideau mists an even coat of SEM 38203 black as the guide coat. Guide coat is used as a visual aid to help identify defects and low areas in the bodywork.
10. Brideau uses a long board made of balsa wood, shown here, to work the doors and quarters after the guide coat has been applied. This initial sanding reveals high and low areas that will need additional bodywork.
11. Brideau employs a straightedge to help verify the flow of the panels.
12. The guide coat has revealed a typical Fox body stamping flaw in the front fender that will need a small amount of filling to correct.
13. Brideau uses masking tape to help define and protect the body lines as he works the surface. This prevents irregularities and ensures crisp body lines, especially in this highly visible area.
14. Using the best-quality fillers, along with proper mixing and application, is very important to a great paint job because uncured body filler under the paint will show up in the future as a defect. Following the manufacturer’s directions is important to proper curing. If you use too much hardener, the filler will cure too quickly and not be workable. If you don’t use enough hardener, the filler will not completely cure and will have to be removed and redone.
15. Here Brideau has found a low spot at the edge of the door and quarter-panel. He used a pencil to outline the area, then sanded the poly primer to ensure good adhesion of the body filler.
16. Filler has cured and is ready for sanding. Brideau takes a long board using 120-grit paper to perform initial cutting. Notice how he blends the door and quarter-panel.
One of the fun parts of the project is deciding on paint color. It’s good to make this decision in the early planning stages for several reasons. An example would be if you choose yellow as your final color. Yellow requires the painter to use a white sealer because a dark gray sealer would require twice as much of the yellow paint to achieve the correct final color. Selecting a solid, nonmetallic color has the benefit of allowing the panels of the car to be easily painted separately without fear of the color looking different from panel to panel. Just make sure to stir the paint well every time you use it.
Lighter nonmetallic colors such as white and yellow are more forgiving and don’t show flaws as much as darker or metallic colors do. They do, however, require excellent body gaps. Any flaws will stand out because the lighter color of the panels is in contrast to the dark body gaps.
If you are not a seasoned painter, metallic finishes can be a challenge. An inexperienced painter can end up with “tiger stripes” in the finish work if he or she is not spray gun savvy. As a word of caution, it’s a good idea to leave light metallic colors to the professionals because they show flaws worse than anything else.
Once all the metal and bodywork are finished, Brideau preassembles the exterior of the car, including trim pieces. “Many times preassembly is not taken seriously,” he says. If this important step is left out, people can end up with some nasty surprises during final assembly. Some parts will need to have a bit of clearance for the paint. A few layers of masking tape can be used to simulate the thickness of the paint.
One technique that seasoned restorers use during preassembly is to drill a small pilot hole in a hidden location. This is done once the gaps are set and bolts are locked down. Pilot holes ensure proper panel alignment when it is time for final assembly. An example would be drilling a 1/8-inch pilot hole through a door hinge or fender/hood/decklid mount in a hidden location, then using an old drill bit as an alignment pin when it’s time to do final assembly and hang the doors and fenders.
Speaking about final assembly, Brideau suggests the use of nylon flat washers beneath the bolt heads during the assembly process, which prevents any witness marks in the panel during preassembly as well as final assembly. “You don’t have to crank the bolts down. You want them to be representative of the way they will be at final assembly,”
Brideau cautions, “Be sure to give the paint reasonable time to cure. Normally a week at temperatures of above 65 degrees F will work. By the time the paint has cured the nylon washers shouldn’t leave marks in the paint.”
He goes on to say, “Those five or six fender bolts along the top of a Mustang fender really show. Elsewhere in hidden locations it’s not such a big deal.”
Time to Paint
“With modern urethane paints, follow the manufacturer’s instructions for mixing the paint with the activator. The activator produces the chemical reaction and is what makes the paint crosslink. And that crosslinking is what imparts the strength, durability, and adhesion of the paint,” says Brideau.
A dry air supply is important. Brideau says, “If you have moisture in the air supply, the activator will be attracted to that moisture instead of the paint. The moisture will rob the paint of complete crosslinking.”
The most optimum air supply will have significant distance between the air compressor and the water separator, according to Brideau. He suggests aluminum or copper pipe between the compressor and water separator because the air needs to be cooled for the water separator to work properly. The separator is only able to remove condensed water droplets, not water vapor. Heat conductivity of the aluminum or copper will facilitate the cooling of the compressed air so that the air/water separators can do their job.
What’s more, you need a drain at the low points in your air supply so moisture can be drained from the lines. Brideau says that you should not use PVC plastic plumbing because it has very low heat conductivity and there is a risk of explosion.
“You might feel you don’t have a large enough shop for a lengthy air supply,” he says. “However, you can zigzag the plumbing up the wall to give it length and the opportunity to purge moisture. This gives the air a chance to cool off like a big air conditioning coil.”
Once you have a system that removes most of the moisture, Brideau highly recommends that if you are going to spray urethane paint, you should add a desiccant system, such as the DeVilbiss DAD-500, which absorbs additional moisture. The DAD-500 greatly reduces the risk of moisture in the paint and expensive paint damage. It removes oil, water, dirt, and other contaminants from your compressed air to allow a high-quality finished job. With routine cleaning and maintenance, the DAD-500 can help achieve a high-quality finish.
17. Brideau used Glasurit 22 urethane acrylic single-stage paint on Bruce Couture’s Mustang GT convertible tribute car along with the corresponding activator (PN 924-94) and clear urethane (PN 923-109). He stresses following Glasurit’s instructions to the letter. Because automotive finishes are very expensive, you cannot afford to make a mistake.
One of the challenges in painting cars today is staying current on changes in materials due to factors such as tougher environmental legislation. Products you are familiar with may no longer be available, which may require adjusting your methods. Although Brideau has used a wide variety of automotive paint products through the years, he is loyal to Glasurit from BASF, which has given him stunning results on many customer vehicles.
Brideau has found that because of the rich volume of pigment in the Glasurit line, he is able to get full coverage using less material. Glasurit finishes yield state-of-the-art European technology, giving him a blend of speed, ease of use, color match, and durability. He will tell you the rich color and deep brilliant gloss makes Glasurit 22 a world-class finish. “I’ve used other finishes,” Brideau says, “and Glasurit comes out much nicer than anything I’ve ever tried. Just look at Bruce’s Mustang convertible in the paint booth right out of the gun. It looks like glass—like the car was dipped in paint.”
Brideau punctuates why he uses the Glasurit 22 line: “I did this entire car with less than a gallon and got great coverage. First, this makes Glasurit 22 paint a great value. Second, when you add more coats it increases the amount of texture in the finish. On many restoration-type paint jobs, I only need to lightly sand out a few dust nibs and polish to achieve the finish I’m looking for.”
One of the important painting tips Brideau can offer is to spray thin, wet coats and allow the solvents to flash off between each coat. Using a slightly slower activator and reducer will allow the paint to lay smooth, but will lengthen the drying time a little. To test whether the paint is ready for the next coat, Brideau finds a masked area, such as near the windshield opening, and lightly touches the paint on the masking tape. The paint should not feel wet or stringy. If it feels like the tack on the back of a Post-it Note, it’s time to spray the next coat. When you apply too many coats too quickly you can wind up with a dull finish, which many people will say can be color sanded and buffed out. However, it rarely works that way, according to Brideau. “It never looks crystal clear and it will not give you a deep shine,” he says.
When Brideau was painting our Fox Mustang GT convertible he laid down two coats of Glasurit 22 single-stage paint, then, a third coat using a 50-50 mix of color and Glasurit clear. He has found that this 50-50 mixture as a final coat gives a nice surface to color sand and polish.
Brideau has advice for those who are thinking of painting their own Mustang: “I recommend a solid nonmetallic color for someone painting the first time. A solid color base coat/clearcoat option would be a good choice for someone just starting out. The basecoat is more forgiving to spray and will allow the inexperienced painter to practice their spray technique before spraying the important clearcoat.”
18. Brideau carefully mixes Glasurit 22 with the catalyst (activator) per instructions. The paint and activator must be mixed very accurately following the manufacturer’s instructions. Notice the DeVilbiss DAD-500 in the background.
19. Doors are mounted on fixtures like this one for painting.
20. Brideau is applying epoxy sealer to a little bare metal that was exposed during the final sanding.
21. Before spraying epoxy sealer, he uses a tack cloth to gently pickup any remaining dust particles.
22. Brideau uses masking paper to check spray pattern before spraying primer and paint.
23. He masks the edges of the hood to produce a smooth paint transition to the underside.
24. He begins body painting with that first coat of Glasurit 22. Notice the careful attention to all the edges of the body.
25. Brideau applies the first coat of Glasurit 22. Note how he keeps the spray gun perpendicular to the surface being sprayed.
26. He applies the 50-50 top coat, which yields an incredible luster—and without color sanding and polishing if you just want to leave it alone.
27. Check this out: two coats of Glasurit 22 line, then a 50-50 mix of paint and clear on top.
Brideau understands that people want to paint in their garages instead of a paint booth, but he highly discourages it. Most paint systems are engineered for, and require, the airflow of a professional paint booth.
Brideau has already told us about getting moisture out of our air supply. Another important factor is the volume of air needed for painting. Many spray guns on the market today require over 10 cfm (cubic feet per minute). For this you will need a large enough air compressor to keep up with the demand of the spray gun. You will also need a large air line. In Brideau’s shop the air lines are 3/4 inch in diameter until they get near the air/water separators. From there they transition to 1/2 inch in diameter to the paint booth, then 3/8-inch-diameter hose with high-flow couplings. This is where you get the air volume that most modern spray guns need to produce a smooth finish.
28. Once the top coat has cured, Brideau allows the body to sit for approximately a week before doing finish work and delivering the car to Bruce Couture.
29. Here is the result of a well-thought-out plan and meticulous attention to detail. Couture, who has restored this Fox classic, understood what he wanted before tackling this project. He spent years amassing N.O.S. parts, then looked to Fox Restorations, National Parts Depot, Baer Brakes, and Maximum Motorsports to help him achieve this result.
Tools of the Trade
“Most of the work in a great paint job is a lot of careful sanding.” Truer words have never been spoken. This is why Scott Brideau has equipped himself with the important tools of the trade, some of which are shown here. This is a small sampling of the different-length sanding boards specific to the shape, size, and curvature of the body surface he is working on. This is where the artistic side of the job comes in.
Brideau says, “I have been known to craft some interesting sanding blocks to accommodate the area of the body I am working. It’s important to remember that almost no area on a car body is absolutely flat.”
He is always looking for materials of different flex characteristics to build sanding blocks. “On a typical Mustang hood I use a sanding block that is about 27 inches long with only a little flex. I am looking for something that will produce even pressure on the sandpaper across the entire length of the block.”
According to Brideau, this technique comes with experience. As you use different types of blocks, it becomes apparent what is needed for a given area of the body. The Eastwood AFS (adjustable flex sanders) blocks can be used by beginners and pros alike.
About Body Filler
We call this stuff Bondo, which was a 3M brand name for auto body filler back in the day. Otherwise known as body filler, these polyester fillers have a poor reputation not because they didn’t do a good job, but because they are rarely mixed and applied properly. Body filler technology has improved dramatically over the years and, when used properly, will easily last the life of any paint job.
You can apply body filler as thin as you like with good results, but it shouldn’t be used to build new body panels. This is where professional metal work comes into play. It is always suggested that you work a dent to get it as shallow as possible—generally no deeper than an eighth of an inch. Body filler can then be applied, but only to “solid” body panels. This means a clean surface with no rust or holes. Brideau says that he sees many older cars with “dent puller” holes in the body, and the body filler looks like worms coming through the back side of the panel. This leaves areas of exposed body filler that will absorb moisture and eventually bubble the paint.
It is important to remember that the expansion properties of steel and body filler are different. This is most readily seen when the quarter-inch-deep roof seam that was previously filled with body lead is replaced with body filler. The abrupt change in thickness of the body filler will telegraph through the paint the first time the car sits in the sun. This effect can be minimized by avoiding abrupt changes in body filler thickness, which brings us back to the foundation of good metal work. We have seen entire Mustang bodies covered with filler, which might seem alarming. However, a paper-thin layer of filler will last the life of the paint.
Body filler and hardener (also known as a catalyst) must be mixed per the manufacturer’s instructions. This works best at normal ambient temperature, meaning 68-75 degrees F. For best adhesion, apply body filler on clean, rust-free, sanded metal, or on top of epoxy primer that is one or two days old. In cold weather, warming the body filler with a heat gun to above 70 degrees will make it so much easier to mix and apply.
When filler has partially cured to a cheddar cheese consistency, begin working it with a 10-inch half-round Surform blade, known in the industry as a cheese grater. Use this tool to take down the obvious high areas in the filler, then use 80-grit sandpaper to work the filler to the shape needed to blend the repair to the surrounding area. Try to leave a little bit of material so you can work your way toward finer grit paper. The grit of sandpaper you finish with depends on the primer surfacer you use. You should typically finish sanding with 180-grit if you use epoxy or urethane primer. If you use polyester surfacer, you could finish the sanding with 120-grit.
30. Brideau has filled this low area with Evercoat Rage Ultra and is shaving the filler with a cheese grater. First cut should look like this.
31. Once filler has been cut down to size, he carefully works the area with a sanding block. He is careful not to damage the flare on the fender.