Spray Machine FAQs

Find answers to frequently asked questions about spray painting machines here, including the best spray gun for painting walls, how to use paint sprayer accessories and tips on caring for your machine. Whether you’re considering an HVLP spray paint gun or an airless model, learn about the different electric spray paint guns available at Dulux Decorator Centre to find the best tools for your decorating job. For more advice, visit our spray techniques page.

• What is the difference between Airless and HVLP?

  Airless spray pumps the liquid paint directly through a spray tip, HVLP using a high-volume flow of air at a low pressure to create a spray pattern. Airless is better suited to applications that require large areas to be painting quickly, airless is more suited to.

• What is the difference between 110V and 240V?

  This is the operating voltage of the machine, 110V machines are considered safer for use on sites where the machine may not be connected to a supply regulated by an RCD/fuse box and in the event of a shock, 110V is more survivable.

• My sprayer is no longer pushing spray through, why might this be?

  This could be due to a blocked filter at the intake, pump or gun or the check ball valve being stuck above the intake (if airless). In HVLP machines this can be due to a dirty air nozzle and needle set.

• Do I need to thin my paint before using a sprayer?

  Paint can be thinned in accordance with the instructions given in the product datasheet and it is recommended that paint is checked for how it flows off a paint stirrer for example prior to spraying it. A particularly ‘stiff’ or ‘stodgy’ feeling paint that does not flow easily should be thinned.

• How do I know what pressure to use?

  Paint can be thinned in accordance with the instructions given in the product datasheet and it is recommended that paint is checked for how it flows off a paint stirrer for example prior to spraying it. A particularly ‘stiff’ or ‘stodgy’ feeling paint that does not flow easily should be thinned.





Spray Accessories

• What do the numbers on the tips mean?

  The numbers indicate half the spray pattern width in inches and the size of the hole in the tip in thousandths of an inch e.g., 517 = 10” wide spray pattern when the gun is between 10-12" from the wall, with 17 thousandths of an inch hole. The finer the material you are spraying e.g., varnishes, the smaller a hole (and lower pressure) needed to achieve a good spray pattern. Conversely, higher build materials (such as masonry and intumescent paints) will require a tip with a larger hole, so you are not using the maximum amount of pressure the machine is capable of to spray.

• What filter do I need?

  This depends on what you are spraying. The more sensitive the finish is to showing imperfections (such as varnishes and high gloss finishes), you will need to use a series of filters with a higher level of filtration compared to if you were spraying higher build films.

• When should I replace a tip?

  You should replace a filter tip when the width of the spray pattern has decreased by 25% e.g., a 617 filter tip should deliver a 12” wide spray pattern, when this reduces to 9” the tip should be replaced. Worn tips reduce how much wall you can cover and increase paint consumption.

• How do I look after my machine?

  After use, the machine should be flushed with water to clear the intake, pump, hose, and gun of paint. The use of pump lubricants and conditioners can prevent the check valves from sticking as well as preserving the life of intake packings.





Understanding tips & filters

• Tips

  All tips have a 3 digit code that tells you the fan width and orifice size. When the fan size is kept the same, the flow of paint (or coat thickness) can be increased or decreased by using a larger or smaller orifice size – for example, a 511 tip will apply a thinner coat than a 517, but both will provide a 10" fan width. When using heavier bodied paints such as masonry, it becomes necessary to use a tip with a higher flow rate (larger orifice number) to avoid unnecessary tip wear. The images below provide a guide to understanding tip codes and the effects of changing tip sizes and orifices:
  
  

• Filters

  Airless spray machines have 3 stages of filtration; at the suction inlet, manifold and in the gun. This helps to remove particulate contaminants from the paint that may affect the finish, cause unnecessary wear to the machine and spray gun tip and ultimately lead to a blockage. Depending on what you are spraying you need to increase or decrease the mesh count at all 3 filtration points, a guide to this is provided below:
  
  

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