Practice Painting With Water to Refine Technique for Restoring Antique Tractors

Nov 12, 2023

If your last attempt at spray painting left you with a dripping finish and sagging enthusiasm for this restoration job, take a pointer from professional Jim Deardorff. Buy yourself a good high-volume low-pressure (HVLP) spray gun and practice painting with water.

Water? "Yes, water is thinner than paint, so when you get to the point where you can apply water without it running off, you’re ready to paint," Deardorff advises novice painters. "It shows you have control of the gun."

Deardorff recommends taking 5 gallons of water, adding one drop of Dawn detergent (to lubricate your gun's needle adjustment) and "spray, spray, spray. You learn a lot about the attitude of the gun to the surface of the paint with such practice," he says.

Attitude, in this case, is the position of the spray gun relative to the surface being painted. "You want the gun to be 90° to the surface to get full atomization of the paint," Deardorff explains. "Practice will help you develop a memory of how far away to keep the nozzle from the work."

As for purchasing a new spray gun, Deardorff is emphatic that you should invest in a good HVLP gun. "It doesn't have to be a professional-grade gun. You can buy a good gun for around $125 to $150," he says. "It should be an HVLP, though, since this type of applicator does a far superior job applying paint and is also easier to use."

Deardorff says HVLP spray guns operate at much lower cap pressures of around 10 psi (which explains the gun's low-pressure designation). "This compares with 50 psi to 80 psi for conventional guns," he says.

The HV designation indicates this gun's ability to apply high volumes of paint. "You have a higher flow of paint at lower air pressure, which allows you to apply an even, thick coat of paint in one pass," Deardorff says.

Not that owning an HVLP gun will prevent all drips and sags when painting. "You need to pay attention to the location of the spray tip in relationship to the work area at all times," Deardorff cautions.

After purchasing a gun, practice with water to get a feel for the applicator. Start out with the lowest settings on the gun.

"The top knob controls the size (width and height) of your pattern. The knob below that controls the flow of paint into the airstream, thus, determining how much coating goes on the surface," he says. "You have an air adjustment (located at the bottom) that sets airflow through the gun. Turn all three knobs down as low as they go and adjust them open until you get the right application."

Another trick that will help you apply an even coat of paint is using a primer paint that is an opposite shade of your finish coat. For example, if your finish coat is a light color, use a dark primer coat. If the finish coat is dark, go with a light shade of primer.

"A light or dark primer gives a great contrast with bare metal," Deardorff says. "The opposite shade of finish paint allows you to readily see areas where you didn't get a thick enough coat on."

Before you start spraying, be sure to get the correct proportion of solvent to the paint in your mixture. Read the paint can and determine exactly how much thinner you need to mix with the paint. The correct proportion has a direct impact on your paint's viscosity.

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