Types of spray guns, their differences, pros and cons

18/10/2020 | ARPSHOP

Pneumatic spray guns: varieties, principle of operation, pros and cons.

This type of spray gun was the first used to automate the painting process - it remains a tool for high-quality professionals.

The general principle of operation is to supply paints and clear coat from a paint cup to a nozzle through which a powerful air stream passes. The nozzle layout allows the air stream to break the paint droplets into fine dust and carries it out, spraying it in the form of a so-called fan, with a cone diverging from the nozzle.
Manufacturers offer two options of paint cups location: up and bottom.

Pros of pneumatic spray guns

The paint applies in a thin layer.
Easy to set up and use.

Cons of pneumatic spray guns

It is necessary to select the compressor for the spray gun correctly.
Not all paint gets on the surface - some remain in the air, forming a colorful fog.

In the market, we have three types of pneumatic guns that differ in painting technology. The main idea of this technology is the use of pressure to spray paint. The differences include the levels of pressure and volume, which impact on painting performance.

High Pressure (HP) Spray guns

HP is one of the first technology that was utilized to automate the painting process. With the most simplified nozzle design, this technology is considered as the most budget. Air goes to the nozzle and sprays liquid out, using high pressure.

Pros of High Pressure (HP) spray guns

The low price of a spray gun. If you need a reliable product at the lowest cost, HP is the best choice.

High-quality painting.

Cons of High Pressure (HP) spray guns

Low paint transfer coefficient - from 35 to 50%. The rest forms into a colorful mist.

You need a powerful, efficient compressor.

To achieve a thick paint coat, you may have several layers.
This technology is outdated and the least effective.

High Volume – Low Pressure (HVLP)

The idea is the spray gun itself requires a lower pressure (LP), and a higher volume (HV) of air is used to aerosolize and propel the paint at lower air pressure. The airflow with high pressure breaks paint entering the nozzle, but the nozzle’s shape reduces the outlet pressure. This technology increases the paint fan's clarity, and the low outlet pressure allows you to keep the spray gun closer to the surface without risk to blow the previous coat. Due to such technology, the transfer efficiency of HVLP guns rises to 65%.

Pros of HVLP spray guns

The paint applies in a thin layer.
Easy to set up and use.
Higher transfer efficiency

Cons of HVLP spray guns

It is necessary to select the compressor for the spray gun correctly.

Not all paint gets on the surface - some remain in the air, forming a colorful fog.

The gun does not work well with high viscosity products.

Low Volume – Low Pressure (LVLP) Spray guns

This type of spray gun requires low pressure to function. LVLP spray guns deliver superb material transfer efficiency (80%) and, hence minimizing waste.

Pros of LVLP spray guns

Maximum efficiency.
Relatively faster than other pneumatic spray guns.

Cons of LVLP spray guns

Require experienced painters.

RP (Reduced Pressure) Spray guns

RP is an improved high-pressure technology that combines excellent painting speed and high transfer rates. HVLP spray guns had limitations in applications due to the low outlet pressure. In this regard, there was a need for a new spray gun. RP series spray guns appeared in the nineties of the last century. RP technology is suitable for applying all types of paints and clear coatings, especially materials with reduced solvent content such as HS paints. A bigger size of fan provides faster painting time. The optimized high pressure of the RP series spray gun produces the finest spray and topcoat.

HVLP vs. LVLP – What’s the distinction?

What to look for when choosing a hand spray gun?