Compressor for spray painting: which one is enough for your gun

Background

Spray painting is not like tightening a bolt: the gun works for minutes on end, so what counts is the air the compressor delivers continuously, not the air in the tank. The type of gun changes the result a lot, because both the air it uses and the pressure it works at change.

The calculator answers one question only: does the compressor give enough air, at the pressure needed? The motor’s duty cycle serves only to rule out sustained continuous use; the air quality is shown next to each compressor, but the calculation does not check it.

How to use it

1. Choose the gun from the list, or enter consumption and pressure from its data sheet.
2. Enter the length and internal diameter of the hose.

Three guns, three results

With 10 m of hose and 10 mm internal diameter, the minimum diameter the Metabo manual gives for the full performance of its guns [73], the manufacturers’ declared data give:

• Conventional gun, Metabo FSP 600: 240 l/min at 4.5 bar [46]. Nine compressors give it continuously according to the declared data, all Güde models with delivered air declared at several pressures: two on 230 V (Airpower 675/8/100 ED-SILENT and 551/10/100) and seven three-phase on 400 V; the calculator above lists them with their sources. With smaller compressors, from a full tank the calculation gives from about 20 seconds with 24 litres to one minute or more with 50 litres, depending on each one’s delivered air.

• HVLP gun, Metabo FSP 600 HVLP: 170 l/min at 2 bar [47]. Eighteen compressors give the air needed according to the declared data: fifteen Güde models (eight on 230 V and seven three-phase), which the calculator lists with their sources, and these three:

  • Einhell TC-AC 420/50/10 V [64][65];
  • Einhell TE-AC 430/90/10 [66][67];
  • Scheppach HC52DC, with the curve of its archived 2019 page [71].

  The Einhell TE-AC 270/50 Silent Plus comes close, about 167 l/min at that pressure [14][15]: not enough continuously, but from a full tank the pressure drops slowly.

• LVLP gun, Metabo FSP 600 LVLP: 136 l/min at 1.6 bar [48]. Twenty-one compressors give the air needed according to the declared data: the eighteen for the HVLP gun and

  • Einhell TE-AC 270/50 Silent Plus [14][15];
  • Einhell TC-AC 240/50/10 OF [10][11];
  • Parkside PSKO 248 B1 [21].

  Two margins are small: about 10 l/min for the Einhell TC-AC 240/50/10 OF and 6 l/min for the Parkside. A longer hose, a narrow fitting or a filter is enough to lose them.

In terms of air quantity, the data mainly favour low-pressure guns: they ask for less air and at a lower pressure, where compressors deliver more.

Open the HVLP example in the calculator and try the other guns.

Enough air does not mean continuous use

A compressor’s motor has a declared duty cycle. The Einhell TC-AC 240/50/10 OF declares S3 25% [11][76]: the motor may run for at most 25% of each cycle, so on average it delivers at most 60 l/min, a quarter of its 240 l/min of declared intake air. With the LVLP gun, which asks for 136, the air is enough but sustained continuous use goes beyond the declared cycle. How long the tool can work and how long it must stop also depends on the pressure at which the motor restarts, which the manufacturer does not declare: the calculator does not estimate it.

The Scheppach HC52DC declares continuous duty (S1) [75]. For the other four compressors the duty cycle is not declared in the sources we have, and the calculator says so next to each one.

Oil-free air

The Metabo manual asks for clean compressed air, free of condensate and oil, for these guns [73]. Metabo’s compressed-air guide points to specific filters for tools that need oil-free air and refers to the tool’s manual; it also notes that condensate collects in the tank [19].

The calculator shows the gun’s requirement and each compressor’s declared lubrication, but decides nothing on that basis: an oil-lubricated compressor is not excluded automatically, and an oil-free one does not by itself make the air suitable for the gun.

What to know first

• Declared values: consumption and delivered air come from the manufacturers’ data sheets. At low pressure, delivered air is read between the declared points, without extrapolating.
• Compressors with a single value: those that declare only intake air, or a single delivered-air value, are in the calculator’s table but cannot be estimated with the same precision. We explain why in intake air and free air delivery.
• Airbrushes: they use small, dedicated compressors, which this site does not cover yet.
• Left out of the calculation: filters, condensate separators and regulators, which add losses.

How we do the sums: where our data comes from.