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Airbrushing Jersey-style Graphics, Part Two: Mixing It Up
By Jim Hingst
Note: “Airbrushing Jersey-style Graphics, Part One” can be found in the June 2010 issue of Sign Builder Illustrated.
Sign makers use a variety of paints for airbrushing graphics on cars, motorcycles, and helmets but Julian “Mr. J” Braet recommends using either 1-Shot or T.J. Ronan lettering enamels. To prevent your airbrush from clogging, you may want to select an airbrush with a .5mm tip to handle the thicker paints. Be sure to read and heed all of the paint manufacturer’s technical bulletins before putting anything through your airbrush.
Before he starts painting, Mr. J mixes all of the colors that he uses. That way, he can switch colors faster. While some sign makers thin their paint with mineral spirits or turpentine, Mr. J says that you’re much better off using the paint manufacturer’s reducer, which is specially formulated to work with the paint.
The recommended ratio of paint to reducer will vary. Many start with a 50 percent reducer to 50 percent enamel mixture. Generally working wet on wet, Mr. J suggests using 60 percent 1-Shot 6002 high-temp reducer to 40 percent 1-Shot lettering enamel. The high-temp reducer evaporates more slowly, which can help prevent the paint from clogging at the tip.
After you mix your paint, don’t forget to strain it using either a conventional paint strainer or the mesh from panty hose. Any globs of paint will clog your airbrush.
Prep Work
One critical step to painting durable graphics onto vehicles is surface prep. “If you don’t prep the surface properly,” cautions Julian “Mr. J” Braet, “you’re just asking for a nightmare.”
How you prep the surface prior to painting will depend on the type of surface that’s to be painted. To prep an older painted vehicle, you’ll need to wash the surface with detergent and water and rinse the surface with clean water. Then dry the substrate with clean paper toweling or lint-free cloth rags.
Next wipe the surface down with a solvent. Many painters will use a wax and grease remover to do this. Warning: Solvents can be absorbed through your skin and into your blood stream. For this reason, many sign makers will wear latex gloves, when prepping a surface with a solvent cleaner. As another option, Mr. J recommends using Rapid Prep, a solventless cleaner. Since wax and grease remover often leave an oily residue, you should do a final cleaning with isopropyl alcohol.
Scuffing the Surface Before Painting
“In most cases you won’t need to scuff a vehicle surface before painting,” says Mr. J. “Generally good surface prep is all you need.”
An exception to the rule is painting on an automotive surface that has been newly painted and clear coated. You’ll need to knock down the gloss on that nice shiny surface, roughing it to give it a little tooth so the paint adheres well. It’s important to thoroughly clean the surface first, before scuffing it up; otherwise, if you scuff up a dirty surface, you’ll drive the dirt into the paint and cause paint adhesion failure.
To scuff the substrate, some pinstripers use an abrasive household cleaner (such as Ajax®) to scuff up the paint. Another option is to wet-sand the area with 600-grit wet sandpaper. Don’t sand the surface dry or you’ll sand too deeply. Water lubricates the substrate, preventing deep scratches.
Only sand in one direction. Sanding in circular pattern could leave circular scratches that could show up after clear coating.
When you’re finished, the surface should have a dull appearance. If any areas are still glossy, you need to rework the panel.
After you’ve completed scuffing the panel, wet the surface, and then thoroughly dry it using paper towels. Failure to dry the surface could result in water spots.
Before painting, give the panel one last thorough cleaning using wax and grease remover, followed by cleaning with isopropyl alcohol.
When spray painting or airbrushing, keep your grubby hands off of the surface that you will paint. Your skin is very oily, and these natural oils can contaminate the surface, which can show up after painting and clear coating. A good habit to get into is washing your hands frequently with soap and water.
New Graphics on Old Paint Jobs
Paint won’t stick to peeling paint or rust. Any rust must be completely removed before you start painting. If it isn’t removed, the metal will just start rusting again. If the paint is peeling, the primer may be the cause. To properly correct the problem, you have to sand the paint in the damaged area all the way down to the bare substrate.
In most cases, if the vehicle surface is in bad shape, it should be taken to a body shop for repair prior to decoration. After removing the failing paint or rust, you have to go through all of the painting steps, just as if you were painting a new surface—starting with primer. Primer helps cover up surface imperfections, helps the paint bond to the substrate, and helps prevent rust.
After you prime paint a surface, you need to sand it. Sanding the primer or sanding between coats of paint roughs up the surface and ensures a good bond between paint layers. Use a fine-grit sandpaper (such as 320-grit or finer).
Painting should be done shortly after sanding, before the dust has a chance to settle. After sanding, wipe the surface completely, using a tack cloth.
Sanding a fiberglass surface—or any plastic for that matter—can generate static electricity, which can attract dust. To kill the static charge on the surface, some painters use a damp rag for wiping.
If you’re going to paint new graphics on an old surface, thoroughly wash the substrate with detergent and water. To remove any wax or other contamination, you’ll need to prep the surface with a wax and grease remover.
After saturating the surface with the remover and waiting a few minutes, use a clean towel to dry the surface. (Note: The toweling will mop up the solvent and any contaminants on the surface.)
Since some solvents can leave an oily residue, complete your surface preparation by wiping the surface with denatured alcohol.
The next step is to scuff up the surface with a fine sandpaper or Scotchbrite pad. Then some painters choose to first spray a base coat of white or black, before painting their graphics. Use a white base coat for light colors and use a black base coat for darker colors.
Some base coats and clear coats are designed to work together. With these systems, the clear coat should be sprayed shortly after the base coat is painted, so the two can crosslink. The waiting period can be as little as twenty to thirty minutes.
Masking Materials
You can use several different types of masking materials, including pressure-sensitive ones. In addition to vinyl professional-grade paint mask, Mr. J uses a variety of other pressure-sensitive products in painting his Jersey-style graphics. Onto vehicles These masks include: paper and film application tapes, masking tape, and blue fine line tapes.
Airbrush artists also use various types of loose masks and stencils. When using a loose mask, some overspray blows underneath the masking. The advantage of a loose mask is that it gives you a much softer edge and smoother transition, so that your work doesn’t look as if you used a stencil to paint. Loose masks can be cut from paper photocopies, or you can overlay a drawing with a thin film (such as 3-mil acetate), and cut the mask into sections.
Regardless of what type of mask you use, many sign makers and artists hand cut masks using an X-Acto® knife with a #11 blade. When cutting a mask, as soon as you notice that the blade is getting dull, change it. A sharp blade ensures that you will cut a clean edge.
About Paint Mask
Available in a variety of colors, vinyl paint mask is a specialized product with a removable adhesive. While many paint masks are comprised of cheaper monomeric vinyl, higher grade polymeric vinyl paint masks are also available. “I use the ProGrade mask because I can easily cut fine detail,” Mr. J says. “The better grade of mask is also more conformable, so I can use it on curved surfaces, such as a motorcycle tank.”
After cutting the vinyl paint mask on a plotter, you should reverse-weed the film to create a stencil. Using a low-tack application tape, the stencil is then transferred to the substrate, and the graphics are painted.
When applying the paint mask, make sure that the edges of the masking fit tightly against the surface. To do so, resqueegee all of the edges after removing your application tape. If the paint mask is lifting, paint will blow back underneath the edges.
If you need to apply the mask over a rub rail or another obstruction, you can cut the paint mask where it is not conforming to the surface. If you have to slit the film with a knife, be careful not to cut the customer’s paint job. Where you cut the film, reapply it to the surface and fill in any gaps with a good quality masking tape. It makes no sense to save a few cents buying a cheap tape because paint can soak through and onto the finish. In some cases, when paint soaks through, it permanently bonds the tape to the substrate, making tape removal impossible. Cheap tapes are also prone to leaving adhesive residue on the surface.
Before you start painting, be sure that you mask off any areas that could be damaged by overspray. Anytime you atomize anything, particles go airborne. This is especially true of paint. Professional painters use a professional grade of masking material, which is available at an automotive body shop for wholesale. Although some people use newspaper to mask a surface, paint can penetrate the paper to the vehicle substrate. Using a cheap substitute can be a costly mistake.
Wet On Wet
After the paint mask is applied, Mr. J coats the open area of the stencil. He often starts working by rolling on a base coat with a three-inch foam roller. You can also use a flat to paint the base color.
Sometimes the coating of paint that you roll on has tiny bubbles in it. To eliminate them, Mr. J recommends running the roller over a sheet of paper after applying the coating. This removes some of the paint from the roller. Then reroll the surface. This smoothes the surface of the paint.
When painting, Mr. J likes to work wet on wet. After waiting five minutes for the paint to tack up, he then starts shading the graphic using his Iwata airbrush. By spraying on the wet paint, the colors blend together better.
In mixing lettering enamel for your airbrush, you want the consistency of the paint to be that of milk. When painting over a pencil sketching, the paint should be thick enough to cover the pencil lines, but not thick enough to clog your airbrush.
After he’s finished airbrushing, Mr. J only waits ten or fifteen minutes to remove the masking. Removing the mask before the paint dries is very important. If the masking stays on too long, a skin can form and bridge onto the paint mask. If this happens, you can tear off some of the dried paint along the edges of the graphic.
As you remove the paint mask, be very careful so the masking doesn’t touch any wet paint. This could leave a noticeable mark, requiring you to touch up your work.
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