How to Paint Your Car With Single Stage Paint

PAINTING YOUR CAR WITH SINGLE-STAGE URETHANE PAINTS

BY NICK CAPINSKI

A common question we hear from hobbyists is, “I want to paint my car. What products do I need?” This seems like an easy enough question, but with so many primers, paints and clear coats available, there are a lot of variables that come into play. To reduce the confusion, Eastwood developed its own line of single-stage urethane paints with the first-time painter in mind. This is a professional-quality paint system that’s easy to mix, easy to apply and easy on the wallet. Our guide to single-stage automotive painting walks you through the process so even someone who’s never painted a car before can Do the Job Right.

Single-Stage vs. Two-Stage Paint

Most automotive paints involve a two-stage system. One first applies a basecoat, then adds a clearcoat layer to give a glossy finish and UV protection. A single-stage system, on the other hand, is formulated to provide these qualities in the color coat. There are several advantages to this for DIYers and beginners, not the least of which are the time and money you save compared to two-stage painting. Although the durability of single-stage paints was once considered a drawback, significant strides have been made in recent years to improve the longevity of these urethanes.

Single-Stage Paint Mix Ratios

Understanding mix ratios is something that often causes confusion. To clear up that issue, Eastwood single-stage urethane paint comes in a gallon can filled with three quarts of reduced paint. Simply pour in the one quart of activator and stir to have a full gallon of sprayable material. Since single-stage urethanes are basically clear coat with color pigment added, these paints can be sprayed as-is. Clear coat can also be used afterward for additional shine and protection.

When repainting a vehicle, you will either strip the vehicle to bare metal or paint over an existing finish. Depending on which route you decide to go, there are different primers you might use as a foundation.

Single-Stage Painting Over Bare Metal

Most full restorations involve stripping the vehicle down to bare metal. This allows you to see what’s hiding under the existing finish and ensure any damage is properly repaired. Because bare metal starts to rust almost immediately, it’s a good idea to apply a primer as soon as possible.

With Eastwood’s single-stage urethane system, apply Eastwood epoxy primer over bare metal. This direct-to-metal primer offers excellent adhesion to bare metal and provides a proper foundation for your paint job. The 1:1 mix ratio makes it easy to mix (one part primer to one part catalyst). Unlike other epoxy primers on the market, Eastwood’s epoxy primer can be easily sanded two to three days after application. It can be top-coated from 30 minutes after application up to five days later without sanding. If top-coating after five days, a scuff sand is required.

Eastwood epoxy primer offers good filling characteristics, but if you need a higher build, it can be top-coated with our 2K Urethane Primer. This primer offers high-build capabilities to fill imperfections and is very easy to sand.

Painting Single-Stage Paint Over Existing Finishes

The other scenario when single-stage painting a vehicle is to paint over the existing finish. This practice is perfectly acceptable as long as the existing finish is solid and in good shape (i.e. not flaking or cracking). If the vehicle has been repainted multiple times over existing finishes in the past, it is generally best to strip the vehicle down. If you’re unsure about hidden repairs under the finish, it’s also a good idea to strip the vehicle down.

Should you conclude that your vehicle’s finish is solid enough to paint over, you have two options: Eastwood epoxy primer or Eastwood 2K urethane primers. For both these primers, thoroughly clean and degrease the existing finish using Eastwood PRE Painting Prep, then sand it with 320-400 grit sandpaper (be sure all traces of wax are removed prior to sanding). After sanding, clean and degrease again.

If there are areas with bare metal showing, apply a coat or two of Eastwood’s epoxy primer. If the sanded surface did not expose bare metal spots, you can apply Eastwood’s 2K urethane primer. This primer has a 4:1 mix ratio (4 parts primer to 1 part activator). Furthermore, the primer’s high-build characteristics will allow you to block sand your vehicle and ensure that everything is smooth. Eastwood urethane primer is also available as a 2K Aero-Spray® High-Build Aerosol Primer and as part of the OptiFlow Roll-On Primer System, giving you two other options for a good paint foundation without the need to use an HVLP gun.

Before block sanding, apply a light coat of guide coat to highlight any problem areas when sanding. Guide coat is simply a different color primer or powder that is applied to the surface. During sanding, low areas will be highlighted by the guide coat left behind.

Applying Eastwood Single-Stage Urethane Paints

Prior to applying your color, ensure that you have thoroughly prepared the surface for paint. A common saying you hear when talking about paint is that “the prep work makes or breaks the paint job” — and truer words have never been spoken. After cleaning and degreasing the surface to be painted, sand with 320 grit, working your way up to 600 grit. Re-clean before applying your color.

Eastwood’s single-stage urethane painting system offers a 3:1 mix ratio — thoroughly mix three parts single-stage urethane paint with one part 21856ZP Activator. No additional reduction is required, although we do offer a urethane reducer that some experienced painters may want to add to increase flow out. However, a reducer is generally not needed for beginners, and it may increase the likelihood of the paint running if added. Mix only enough paint as you will be using since Eastwood’s single-stage urethane paint may begin to gel after approximately two hours (at 70°F).

When setting up your HVLP paint gun, hold the gun 6 inches from the surface and try to get a fan pattern that is approximately 6 inches wide for spraying automobiles. If you’re spraying smaller objects, a 4-inch pattern is usually ideal. We recommend that you practice with different fan patterns before you begin spraying your project.

When spraying, be sure to keep the gun parallel to the surface you’re spraying. If you’re spraying a solid or metallic color, you should use a 50% overlap on each pass. For candies and pearls, you usually want to use a 75% overlap. When spraying, you should walk with the gun, keeping your wrist firm. If you move your wrist, this will vary the gun’s distance from the surface you are spraying, resulting in uneven coverage.

A large part of spraying is developing a feel. The more you practice, the better you will become. There is a fine line between laying the paint on flat and texture-free or having it run off the panel. To get this feel, you must practice and become acclimated to your spray equipment and the products you’re spraying.

Apply single-stage urethane paints in two or three medium-wet coats as necessary to achieve sufficient coverage, allowing a 10-minute flash time between coats. Additional coats may be necessary to achieve total coverage for some metallic colors. A final “fog coat” may be applied with metallic colors to help set an even flake pattern and/or adjust flake orientation. A dry film thickness of approximately 2mm is recommended.

The paint should be dust-free within 10-15 minutes and tack-free within one hour (at 70°F). Recoat any time after the previous coat has flashed or before 18 hours. After 18 hours, paint should be abraded prior to recoating for proper adhesion purposes.

This urethane paint may be applied as a stand-along single-stage system or in combination with Eastwood Urethane Clearcoat Plus Activator as a basecoat/clearcoat system. Additionally, urethane clear may be integrated into a urethane color. When combining the two systems, be sure to activate each side (the paint and the clear) separately, with their own activators at the correct mix ratios, before blending.

When used as a single-stage urethane paint, this coating may be wet-sanded and polished for increased depth and gloss like any other urethane topcoat. Care should be taken when lightly cutting metallic colors to prevent disturbing the aluminum flake.

If you have further questions about how to apply single-stage paint, call the Eastwood tech team or visit our How-To Center. We are pioneers in DIY automotive painting and have the paints, equipment and knowledge you need.

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