Spray Paint 101: How to Get a Professional Finish

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If you’ve got something difficult to paint, something that's out of the ordinary, chances are good that somebody makes a specialized spray paint to coat it. There are paints to spray automotive quality finishes, coat fabrics, galvanize metal to protect it against rust, give metal a retro look like the inside of a 1960s car trunk, spray your firepit or your barbecue, and perform other tough coating jobs.

But the thing is, you have to use the paint correctly. Spray paints are among the most expensive coatings you can buy. Many of these coatings are specially formulated to provide increased adhesion, wear resistance, or resistance to high temperatures.

If you do a poor job applying the paint, you’ve wasted your money.

Given how chemically sophisticated specialized spray paints are, it’s ironic that people will often achieve poor results using them. That needn’t be the case. Some surprisingly basic rules will see you through almost all spray painting jobs.

We review these rules below and review of some of our favorite specialized coatings.

Spray Paint 101

Start Clean

Dirt, dust, wax, and oil all form a barrier between the paint and the substrate. Brush or vacuum away dust. Wipe off or wash away dirt. Finally, wipe the surface with a suitable solvent. This may be anything from denatured alcohol to mineral spirits. Some manufactures recommend proprietary spray cleaners and degreasers before using their spray paint.

Maintain Chemical Compatibility

Primers and top coats work best when they are from the same manufacturer and are chemically compatible. For example, in most cases an alkyd-resin primer should be used with an alkyd-resin top coat. Read the technical data sheet or the product's instructions, or call the company's technical service number, for more information on this. There are rare exceptions. Some primers are formulated to work with more than one type of top coat. And for that matter, some topcoats can receive a coat of clear gloss of a different formulation. In some cases, an acrylic clear coat may be applied over an alkyd topcoat (that would be three coatings: primer, topcoat, clear coat).

Watch the Time Interval

When applying multiple coats of paint, such as following the primer with a topcoat, or applying a clear gloss over the topcoat, use the time interval between coats specified by the manufacturer. Again, look for this information either on the technical data sheet, on a video link provided by the manufacturer, or by calling the company's technical service number.

In Most Cases, Prime

Primers perform a number of important functions. First, they provide a surface with a texture that helps the top coat bond. Second, they are formulated with aggressive solvents and a resin that helps this first coat of paint bond tenaciously to the substrate. In the process, the primer forms a foundation for the paint coats to follow. Finally, the primer is chemically formulated and has a porosity (or lack of it) that helps the topcoat flow out evenly over it. This helps the topcoat look as good as possible.

Sweep, Don’t Point

Never hold the spray can in one position and shoot paint at the object. Instead, point the nozzle away from the object, press down on the spray button, move past the object, and stop or move back. That is, sweep the paint over the part. Holding the spray nozzle down and holding still will produce a run in the paint.

Test Drive

If you've never used a particular spray paint before, especially a specialized type, test drive the paint before applying it on the most visible areas of what you are painting. Or test drive the paint on a block of wood or even some piece of junk with an unusual shape. You want to gauge the distance from the object to hold the can and the speed to sweep over the surface. It may take you a couple of test shots before arriving at the optimal distance and speed.

Protect Yourself

Spray paints contain powerful and volatile solvents and other chemicals. Use them in a well-ventilated area and wear a suitable respirator designed for spraying paint.

Some of Our Favorite Spray Paints

Here are some of our favorite problem-solving spray paints. We've taken each one for a test drive and we like what we found.

Rust-Oleum's Rusty Metal Primer is a king size can (24-oz) of painting power. It has an unusually-wide spray nozzle that provides a wide band of paint that makes it feel like you're using a spray gun. The paint quality is outstanding, with good leveling and the ability to hide surface pitting and small imperfections. An added bonus of this alkyd formulation is its ability to wrap and flow around sharp corners.

Cast Blast spray paint is a metalized acrylic lacquer that provides a slightly matte texture and medium sheen. It’s intended for auto restoration to impart a factory-fresh appearance that mimics cast iron parts fresh from the foundry. We found that the product applied evenly and sprayed nicely. It doesn't require much practice to get an evenly coated part, but it doesn't hurt to take a test run with the material on the part's back before spraying its front.

Krylon describes its paint as delivering a coarse stone texture to the sprayed part. The spray does deliver a rough surface, vaguely reminiscent of stone, but if you want a more accurate stone finish, we would suggest blending layers of matt finishes of various colors and especially using primers and matte clear coats. To our eye, we would describe the Krylon product as an artistic spray paint that does a good job of filling surface imperfections.

Formulated for high-temperature parts on motorcycles, this unusual paint produces an textured matte black finish with a temperature-resistance rating of 500 degrees. The paint applies easily and covers well.

Alumi-Blast is an apt name for this low sheen coating that looks realistically like cast aluminum that has received a light brush-off abrasive blast at the factory. It's intended for auto restoration but becuase it leaves such an attractive surface with a formulation that includes a large amount of aluminized paste, we could see it as being an attractive general-purpose metal finish. Bonus: it's heat resistant to 250 degrees.

Eastwood's unusual 3-step paint process begins with a light coating of the base gold coat, followed by a red-zinc colored coat, and finally an application of green-zinc colored paint. We were skeptical of the product, but after a test run (on a poplar wood block with a green cast to it, no less) we find this unusual product lives up to its billing as a coating that looks quite similar to a factory cadmium plated part.

Catalyzed spray paints otherwise known as two-component or 2K are all the rage these days for delivering a spray gun quality coating without a spray gun and associated apparatus, such as a compressor. We were favorably impressed with the Spray Max product. Unsnap the button from its lid and press it into the base of the can until you hear the telltale click that alerts you to the fact that you've broken its seal. Mix as you would normally and spray as you would normally.

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