The following is about painting technology and, in particular, paint spray guns. There have been constant developments in this area over the years. First, we will explain the basic design of a paint spray gun. This is followed by an explanation of the differences between them and the specific uses of each gun.
What is a paint spray gun?
You can apply paint materials of all kinds, primers, or glazes to large surfaces with a paint spray gun. Therefore, it is suitable for paint shops, carpentry or other industries.
Compared to brushes and rollers, it has the advantage of applying liquid materials faster and more evenly. In addition, with its spray mist, it often reaches places where alternatives have difficulty with a complete application.
Due to such advantages, it has increasingly found its way into the private sector to apply large areas of metal, wood, or even walls.
The main differences are in the nozzle sizes that you should use for different paints. These always depend on the viscosity of the colors or primers. The basic rule is the denser the medium, the larger the nozzle.
Structure of a conventional paint spray gun: Parts descriptions
The following is intended to help you understand how a conventional paint spray gun and its parts function during painting. The description proceeds from top to bottom of a standardized gun with a flow hopper:
- Adjustable drip-type sprayer: It sits on a plastic cup that can be unscrewed to prevent paint from dripping out during handling.
- Replaceable plastic cup for the color: This is where you fill the color. It is easy to screw onto the gun housing and can be changed quickly.
- Replaceable paint sieve: Between the gun body and the plastic cup, there is a paint sieve at the bottom to sieve out coarse impurities or flocculations before use.
- Stepless material volume regulation: It is located at the very back of the gun body. It is a regulation screw that allows you to increase or decrease the supply of material from the plastic cup.
- Nozzle and needle: The paint nozzle and paint needle are one unit and are located at the front (nozzle) or extend into the body core (arrow). Using these two elements and the air pressure, the paint comes out in the spray first.
- Stepless flat and round jet regulation: It is located in the middle, and you can regulate it there using a screw so that the spray jet comes out rather round or flat (wide).
- Needle seal on Teflon: The needle seal prevents the paint from running back.
- Body: This is the central part where all components are mounted or integrated.
- Trigger: With this, you operate the gun so that the compressed air is supplied and the spray jet comes out.
- (Rotatable) air connection: This is where you connect the air hose to the gun.
Differences in the design of other spray guns
There are now many spray guns that invoke different methods, each of which you can use to your advantage for various paints and applications. Below are the most common groups of spray guns so far.
HVLP spray gun construction:
A high volume (HL) comes out of the gun simultaneously as low pressure (LP). So here comes out a lot of paint with little pressure supply. The paint atomization is somewhat coarse. But the transfer rate, i.e., how much paint hits the painting surface, is very high. This guarantees perfect and flush paint jobs.
Here you can see how to set up an HVLP spray gun correctly for your application in just a few steps. The disadvantage is the higher air consumption that the gun requires from the compressor as input pressure.
In principle, the design and construction of the gun are just described. With this, you can generally process conventional basecoats and especially water-based paints very well.
LVLP spray gun design:
The LVLP technology originates from the HVLP technology and is, so to speak, a further development. The flat spray head has been modified so that the inlet pressure can be reduced by around 30 to 40%. Otherwise, the design is similar to an HVLP paint spray gun.
It consumes significantly less air, and operating costs are reduced by around 40 % since compressed air generation is the most significant energy cost factor in the entire technology.
The process reduces paint mist and paint rebound. However, the atomization is somewhat coarser. That’s why you will find it preferably in the hobby and private sector.
Airless spray gun structure:
The airless spray gun has a slightly different appearance, which at the same time symbolizes the other technology system of the gun. Namely, it works with much more pressure and only the atomization of the material. The atomization succeeds using the higher pressure between circa 150 and 200 bar.
Often the airless spray gun has a more oversized handle for four fingers with a better grip, a bracket to protect the fingers, and a unique protective cap for the nozzle.
This technique allows you to apply paints and coarse and emulsion materials for walls, for example, which would not be possible with other guns due to the risk of clogging the nozzles.
Which paint spray guns are recommended for beginners?
The established spray guns with HVLP or LVLP technology are recommended for beginners. This is because they are straightforward to operate and use the standard compressors that are often already available in every household for pumping up or spray-cleaning.
Thus, the training is only required to mix the colors, the operation of the spray gun in general, and the subsequent cleaning of the same.
Manual or automatic setup: Which is better?
The manual and automatic setup differ depending on the application. Manual guns will undoubtedly have their advantage when it comes to individual spraying. Especially at home or for smaller and more personal customer orders, they will be predominantly in use here.
In series production, on the other hand, you will increasingly find the automatic setup. Here, the technology is faster, and it is a matter of constant and consistent painting or priming.