Adjusting an HVLP spray gun is the first task to start painting. The operator does not need any special tools but uses the adjustment screws on the gun and peripherals.
Why the HVLP spray gun needs to be adjusted at all and how exactly this works will now be described below.
Why should you adjust HVLP spray guns?
You should constantly adjust an HVLP spray gun to achieve the best spray pattern. This depends on the paint and whether you even use primers or resins with different viscosity, so the pressure must be set differently when painting.
However, if you don’t, the spray pattern can become small or irregular, provoke runnings due to a lot of paint on a small surface, or even clog the nozzle. Here we explain how to clean your paint spray gun thoroughly and free it from deposits.
In this regard, it should be mentioned that water-based paints react more sensitively to changes in settings. Therefore, shining the color can be helpful, but always pay attention to the respective manufacturer’s specifications first.
Adjusting the HVLP spray gun in 5 steps (instructions)
The following are the essential steps when working with HVLP paint spray guns and should be carried out in that order.
Step 1: Set the pressure on the compressor correctly
It would help if you first thought about the correct pressure at the compressor. Depending on the paint and its instructions, you should adjust it.
It can range from 1.2 to a maximum of 3.5 bar, which you can read off the compressor’s pressure gauge and adjust at this screw or handle. Since the HVLP generally requires less pressure, this is usually reduced to an initial range of 1.2 to a maximum of 2.5 bar.
Step 2: Correctly adjust the inlet pressure at the gun
It is essential to adjust the inlet pressure at the gun because the pressure can be somewhat reduced in the feeding hose, especially if it is dimensioned slightly longer. To do this, move the regulating screw located at the bottom of the gun handle.
This must be set precisely and defines the correct air pressure, which the manufacturer of the colors means. Therefore, it is recommended that you use a pressure gauge for a more precise setting directly on the gun to increase the accuracy.
Step 3: Adjust the regulating screw for a spot or wide spray.
Now it’s a matter of getting the right spray effect on the gun. If you want to spray more extensive areas, you need the wide jet. For smaller rooms, it is the spot spray.
You can adjust this function using the adjusting screw, which is either located at the back of the gun body (and is then the upper one) or at the side of the body. This screw regulates the supply of the two air inlets on the side of the spray head.
This transforms the round jet into a flat lateral shape using this supply air. This allows you to spray the surfaces in question generously and evenly.
Use a spray-out such as a piece of cardboard, for example, and then check and adjust the spray pattern according to your wishes. By the way, this procedure always trains you for a correct posture and distance to the painting surface so that you don’t create spray noses or apply paint too lightly.
Step 4: Use the regulating screw to reduce the amount of material used
You don’t always need the material quantity regulation for the paint guns you use. It adjusts the handle to just more or less paint that comes out of the gun.
It sits on the same axis with the needle at the back of the gun. To do this, do the spray-out again with the piece of cardboard, and while turning it, check to what extent you want to limit the stream.
Step 5 (if necessary): Replacing the nozzles
If you have followed all the above instructions but still do not get the desired spray pattern, it may be due to the nozzle size. In this case, you should replace them.
This involves changing the complete set with nozzle, needle, and air cap. After the exchange, you proceed again according to steps 1 to 4.
Do HVLP spray guns have to be adjusted differently than other spray guns?
HVLP paint spray guns have the characteristic that mainly the amount of material used differs. Therefore, the adjustment will often focus on, which could vary from the other guns.
Also, it always needs a little less pressure than conventional guns. Instead of 2 to 3.5 bar, you will only need 1.2 to a maximum of 2.5 bar. Therefore, you will undoubtedly be active at the gun input pressure screw if you were previously used to a higher pressure with other guns.