Tech / Tech Articles

Quick Tech: A Basic Guide to Engine Paint

 

engine

It takes a special kind of paint to survive under your hood.

Engine paint must withstand extremely high temperatures and be able to resist gasoline, oils, and other chemicals. And it has to look good, too—especially if the engine bay serves as a focal point for your hot rod or show vehicle.

94693Fortunately, companies like Dupli-Color, VHT, and POR-15 make paints specially formulated for engines. So what makes for a good engine paint? We asked the experts at Dupli-Color/VHT what to look for in a good engine paint and hit them up for some application advice to ensure the right finish. According to Mark Eichelberger, Associate Product Manager at Dupli-Color/VHT/Tri-Flow, a good engine paint should have three characteristics: heat resistance, gloss retention, and resistance to chipping and flaking.

That’s why engine paint is typically an enamel paint.

Enamel paints typically offer a hard, glossy finish and have excellent color retention. In addition, enamel can provide superior heat resistance—a must for automotive engine use. Because under hood temperatures generally run between 250 and 300 degrees, a good engine paint is usually rated to handle temperatures up to 500 degrees—and beyond. You’ll also find that some companies, such as Dupli-Color, add ceramic resins to its engine paint for added heat dissipation. Ceramic is proven to be extremely effective in high temperature paints for headers and exhaust systems and can even be applied to jet engines.

When properly cured, enamel paints not only offer excellent chip resistance, they also resist rust and corrosion. They are also fairly simple to apply—either by brush, roller, or spray, depending on the paint—making them easy to work with even when your engine is still inside the engine bay. The most common engine paints are sprays and often involve simple “rattle-can” aerosol cans.

Last but not least, enamels can be formulated in a wide range of colors, allowing manufacturers to offer a huge array of options. In many cases, this includes factory-matched colors like Chevrolet Orange, Ford Blue, and Cummins Beige. Like any paint, the final look of your engine paint comes down to proper application—and a bit of patience.

Application Tips

  • Sand the engine thoroughly. You can use a wire brush to help remove old paint and debris.
  • Clean the block with a grease and wax remover prior to painting to remove oils and other chemicals.
  • Wipe down the engine to remove loose particles or use an air hose to clean debris.
  • Start with a high-heat engine enamel primer for maximum corrosion resistance and uniformity of your top coat color.
  • Apply primer and top coat engine enamel color with a light “tack” color first to avoid runs and sags.
  • With spray applications, use a long, sweeping motion to apply the paint evenly and without runs.
  • Continue to apply two more light coats followed by a medium wet coat for the best coverage and smoothness of the paint finish. As a general rule of thumb, a few thinner coats will provide a higher-quality finish than one or two heavy coats.
  • For extra protection, use a high heat engine enamel clear coat applied the same way as the primer and top coat engine enamel color.
  • As always with paint, make sure to wear a mask or apply in a well-ventilated area.
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3 Comments

  1. Pingback: paint the engine - REVscene Automotive Forum

  2. This is a great list of advice, I have built many engines and I always custom paint them for the cars I’m installing them in. I have always used both Dupli-Color and vht and they do have a wide variety of colors. If you take your time and do as they say with small amounts and several coats you can get an absolute Beautiful Finish that will hold up for years to come.

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