Airless Spray Machines atomise the paint under high pressure to push it through the spray tip. It is the combination of product, tip size and pressure that give the flow rate of the product and the fan pattern/size.
From Graco.com: In airless spray, the fast moving high-pressure liquid stream provides the energy necessary to overcome the fluid’s viscosity (resistance to flow) and surface tension (a force that bonds the surface of a liquid together) to form a fine spray. In the depiction of spray from a gun, high pressure forces fluid through a small nozzle (spray tip). The fluid emerges as a solid stream (sheet) at a high speed. When the solid stream hits the air, it becomes disrupted. This disruption breaks the fluid into fragments initially, then ultimately very small droplets that form the spray pattern.
Airless Assisted works in the same way as an airless machine HOWEVER the paint is pushed through the gun at a lower pressure (500-1500 psi) and is partially atomised through a small tip. A small amount of air is added to the edges of the fan using a compressor which gives full atomisation resulting in a softer fan pattern and less overspray. Although with the low pressure tips we wonder whether Airless Assisted is necessary now and are testing this idea.
Conventional spraying uses a compressor to push air at high pressure through spray gun to blast the product through. This high pressure finely atomizes the spray and produces very fine particles which gives a very smooth application, whether it be a clear shellac, varnish or paint. Despite the brilliant results conventional spraying gives the gun is only 30% effective – only 30% of the product goes where it is meant to go with the other 70% is in the air as overspray. This is why this system is used more often or not in a workshop environment where there is extraction and controlled conditions to minimise this.
HVLP & XVLP
HVLP stands for High Volume Low Pressure which means that they apply the paint using airflow under lower pressure than Airless. This maximises atomisation giving greater control, minimal overspray and paint wastage. XVLP stands for Special Extra (X) which just means that there is 60% more air volume and 30% bigger area coverage which gives better overall atomisation.
HVLP & XVLP machines were made for finer work than Airless machines and were used mainly for furniture, cabinets and smaller woodwork projects however with the smaller Airless machines there is less need for them.
There are various 2, 3, 4 & 5 Stage turbines available from a few different suppliers.
These are airless machines that are more robust and powerful than the standard machines. With wider hoses and stronger guns they are able to spray most ready mixed or powder fillers and plasters on drywall, ceilings, walls and other substrates internals & externally. These machines are able to spray at higher pressures and volumes than the smaller machines and are more than capable. These are also available as Electric or Engine Driven.
Have a look at these machines.
Graco Turbo Force HVLP 9.5
The Graco Turbo Force is a great HVLP machine at around £1740 incl vat.
The Tritech T5 is a really robust unit which will be cable of taking on most projects without a problem. The price of this machine is around £1794.00 incl vat
the Q-Tech P-036 is a beast of a machine capable of a 2 gun operation. The price of this machine is around £3402 incl vat