Spray Gun Air Caps, Nozzles and Needles

Spray Gun Air Caps, Nozzles and Needles

Need a replacement nozzle for your sprayer? Not sure which HVLP tip size to use for oil based paint? Want to know what size spray nozzle to use for automotive paint? Here is your guide to determining the best size needle, nozzle and air cap combination (also known as an atomizing set) is best for you!

Brand, viscosity, the type of surface being painted and the thickness of the coating are all factors that determine which size is atomizing set is best for you. You can utilize tools like the Zahn #2 viscosimeter to measure viscocity. The Zahn #2 viscosimeter works by measuring the number of seconds it takes a specific amount of paint, lacquer or varnish to flow through the bottom of the cup.

There are many spray gun tip sizes, so it can be difficult to determine exactly what you need. The spray gun tip size chart at the bottom of this page outlines the different options.

In general, smaller sizes (.8mm-1.0mm) are ideal for small areas, touch-ups, shading stains/ ink and spray tanning. They are best suited for thin liquids, nitrocellulose lacquers and water based paints.

Medium sizes (1.3mm - 1.5mm) are optimal for louver doors, trims and cabinets and oil-based paints.

Thicker coatings, such as industrial primers, catalyzed lacquers and urethanes require larger sizes (1.8mm-2.0mm). Suitable applications include walls and ceilings, stone finishes, texture coating, floor paving paints, splatter and multi-fleck paints.

Use the paint sprayer tip size chart below as a guide for choosing the setup that will yield the best results. Solutions to common problems including orange peel, gritty finishes, blushing and fisheyes may be prevented by proper thinning and choosing the correct size atomizing set.

The recommended combinations of paint sprayer parts in the Spray Gun Tip Size Chart below are highly accurate, though it is advisable to experiment with different combinations to find what works best for your specific application.

Needle and nozzle sets must always match in order to prevent leakage. For example, a 1.5mm nozzle should not be used with a 1.8mm needle. Some needle sizes may be used with multiple nozzles. For example, 1.3mm and 1.5mm nozzles may be used with the same Apollo A7520-1315 needle. Likewise, 1.8mm and 2.0mm nozzles may both be used with the Apollo A7520-1820 needle.

High solids air caps are available in sizes B, C and D. They are designed to increase nozzle pressure for coatings that are difficult to atomize or have higher solids in the liquid.

Coatings with high solids usually have more resin and less volatile organic compounds (VOCs) in order to meet stricter emissions regulations, especially in the aerospace industry. These types of coatings can be more expensive, but require less volume, so they are often more cost effective. One reason many painters have not switched over is that the high solids primers, base coats and clear coats can be more difficult to use.

Surface preparation, proper thinning and air pressure settings are critical for ensuring a top quality result. Turbine systems are particularly well-suited for these types of paints since they emit clean, dry air, a significant advantage over compressed air systems.

Changing atomizing sets is fairly easy and may be necessary when switching from a thinner liquid to one with a higher viscosity. Click here for step by step instructions on how to change atomizing sets in the Apollo AtomiZer A7700 turbine spray gun.

Please note that whenever nozzle sizes are changed, the air distributor gasket needs to be reseated. To do this, pull it out of the front of the air distributor and reinstall it so that it is flush with the front of the air distributor.

Still not sure which size is best for you? Don't hesitate to give us a call at 858-722-1135 for further assistance.

Spray Gun Tip Size Chart