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Tuesday, September 10, 2013

Spray Painting Technique

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Jim Hingst explains the many variables that can make or break a spray painting job...


By Jim Hingst @hingst_jim

In spray painting, there are many variables that can make or break a job. These variables include the air pressure settings for the compressor and the spray gun, the paint volume adjustment,  the fan adjustment and your spray painting technique.

 Before spraying, be sure that you adjust the air pressure from the compressor to the setting recommended by the spray gun manufacturer. Different types of guns will have different air pressure requirements. Typically, this setting  for a HVLP spray gun should not exceed 50 psi.   If the pressure is too low, you will apply too much paint on the substrate, resulting in drips or sags. If the pressure is too high, you could damage the air pressure regulator for the spray gun. 


Be sure to keep the spray gun perpendicular to the surface. Maintaining a consistent distance between the nozzle of the gun and the substrate, and maintaining a constant speed of application will ensure a consistent deposit of paint.  


To properly atomize the paint and attain a smooth finish, you should also adjust the air pressure regulator to the spray gun. Test the spray gun before you start painting to ensure that your gun is delivering the desired spray pattern. The ideal pattern should look like a flattened oval. Adjust the fan width accordingly.

After tuning the gun for the desired results, you are ready to spray paint. The right spray painting technique involves a little more finesse than just moving the gun with your wrist from side to side. When painting in this manner, it is impossible to maintain a uniform distance between the nozzle and the substrate.  The result is an uneven application of paint.   


Rather than a simple wrist movement, the proper technique involves moving your entire arm from your shoulder.  If you want to lay down a uniform coating of paint and end up with a professional-looking job, keep the nozzle of the spray gun at a uniform distance (about eight inches) from the substrate. If the gun is too close, the paint will sag. If the gun it too far away, the painted surface will look blotchy, dull and textured. 

If you are using a masking material, such as the RTape ProGrade paint mask, as a stencil, start spraying on the paint mask and continue spraying over the exposed areas of the design. As you are spraying, keep the spray gun moving. Stopping in one spot painting without shutting off the spray gun will result in heavier deposits of paint that can develop into runs.   


After painting the initial stroke of paint, each subsequent stroke should overlap the previous one by 50%.  Failure to overlap strokes sufficiently could result in bands or streaks.  Excessive overlap results in a heavier coat of paint, which could run or sag.

Whatever you do, don’t stop in one spot. Developing this painting technique is easier said than done and requires practice. 


When you are spray painting, you should first spray a very light tack coat.  After waiting  a few seconds for the solvents in the tack coat to flash off, spray a second heavier wet coat.  The dry tack coat will bind the wet coat to the substrate and prevent the paint from running or sagging.


The speed at which you move your arm will determine the amount of paint that you lay down.  Be sure that the second coat wets the substrate.  Applying the paint too dry will result in an orange peel effect.


As a final piece of advice, get some basic training from someone who knows what he is doing. At the very least, buy a video on spray painting.



About Jim Hingst: After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.

Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer.  Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.

Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for  publications, such as  Signs Canada, SignCraft,  Signs of the Times, Screen Printing, Sign and Digital Graphics and  Sign Builder Illustrated. He also posted more than 325 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published.



© 2015 Jim Hingst

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2 comments:

  1. WinnipegSeptember 25, 2019 at 11:08 PM

    Great blog post...very informative. Thanks for sharing.
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  2. spray paint art secretsOctober 30, 2019 at 9:45 PM

    Nice! Thanks for this great information. Keep updated..we provide videos lessonson painting techniques, tips and more.

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