Rating Spray Tips In Airless Spraying Applications

Rating Spray Tips In Airless Spraying Applications

April 11th, 2018
Eric Emin Wood

Choosing the right tip and size for your airless spraying application is key to achieving a quality finish and make sure the job goes as smoothly as possible. If you find tip selection in airless spraying confusing, we've compiled some insights to ease your mind, achieve better results and finish quality jobs you'll be proud of.

How to Rate Spray Tips

Most manufacturers rate spray tips by considering several factors:

The spray tip size, which depends on the application and tip rating. You should always make sure your sprayer accommodates the tip you'd like to use before purchase. The following tip sizes are suitable for coating materials.

  • BlockFiller and Elastometric.025-.035+
  • Smooth Elastometric and Heavy Latex Paint .021-.025
  • Latex Paint .015-.019
  • Lacquer.009-.013
  • Oil Base Paint .013-.015

What the Numbers on the Tip Mean

Spray tip size is made up of two separate components: the fan size and the orifice size. For example, if you're using an LTX515 spray tip (common tip for spraying latex paint), the fourth character (5) indicates the fan size. If you multiply it by 2, the result is the approximate fan size when you're spraying about 12 inches from the surface. Therefore, this tip would have an estimated 10-inch fan when the tip is 12 inches from the surface being sprayed.

The last two digits (1,5) relate to orifice size in thousands. In this case, the spray tip has a .015 (fifteen-thousandths) opening for the paint to go through. Orifice size is directly related to how many gallons per minute you intend on spraying.

The Coating or Paint

You should always put some thought into the type of material that's going to be sprayed when selecting a spray tip. Use small tips when spraying light coatings such as enamels, lacquers, and stains. Heavy coatings, like external latex paints, need larger spray tips.

Maximum Tip Size With One or Several Guns

The maximum pressure or pounds per square inch (psi) measures a sprayer's stall pressure (the maximum pressure the pump can build).  However, the tip's pressure may vary with the maximum stall pressure. The filters, hose length, type of coating and tip size influence the tip's available pressure during spraying. Some of the standard maximum sprayer pressure ratings include;

  • 2000 psi
  • 3000 psi
  • 4000 psi

Essential atomization pressures are:

  • 2000 psi + for latex paints
  • 1000 psi for lacquers
  • 1600 psi for stains 

Horsepower (hp) assesses the sprayer's engine or motor performance. There are different operating speeds, motor types and torque capacities. Therefore, the horsepower rating usually confuses some distributors and users. However, the motor or sprayer used should match a job's requirements.

Adjusting Spray Pressure

It's recommended to apply minimum pressure to break down the coating completely. You should set the pressure control in a low-pressure setting. Gradually increase it until you atomize the paint. If there are fingers or trails in the spray pattern, you should increase the pressure.

However, one should use a small orifice spray tip when the sprayer's maximum pressure can't attain an ideal spray pattern. To test the pattern's quality, spray them on waste materials or pieces of cardboard until you're happy with the finish.

Control Coating Thickness

Avoid adjusting pressure to thicken or thin a coat. To achieve a beautiful spray pattern, set it to the lowest level. However, if you have an unusually thick layer, move the gun quickly. Select a tip with a small orifice. However, you should ensure that your spray gun can handle it. It should be at least 12 inches from the surface.

When using an airless sprayer, ensure that you;

  • Use an ideal tip for your paint application.
  • Use an appropriate hose length.
  • Apply enough pressure to prevent to avoid over spraying.
  • Avoid "fanning" the gun (It could result in a non-uniform finish).
  • Ensure that you have a minimum overlap of 50%.
  • Point the sprayer's tip at a corner.
  • Begin spraying from the outer edges of a wall.
  • Ensure that the sprayer is close to the surface.
  • Trigger the spray gun on every stroke to avoid making double coats. 

"Gallons per minute" is a typical measurement used to determine the ability of an airless sprayer. How many gallons per minute will the sprayer deliver determines the largest spray tip size you can use. You must also remember that as the spray tip wears, the orifice gets bigger. Because of this, it's generally a good idea to select a spray tip that's one size below the pump's maximum rating, so you don't go beyond it as the orifice gets larger.

Bolair doesn't just sell spray equipment – we're here to make sure our customers maximize their spray equipment to its full potential. If you're having any issues related to your spray equipment (or selecting the right spray tip), our team of industry experts has the knowledge you need to get the job done right.

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