CBS technical guide · Compressed air for painting

What air compressor do I need for painting?

Short answer: for spray painting you need a compressor that delivers more CFM than your spray gun consumes (with a 25–50% margin), stable pressure of 29–45 psi (2–3 bar) at the gun, a tank of 40 gallons (150 L) or more for continuous work, and clean, dry air — no water, no oil — so the finish is not ruined. A 2–3 HP piston unit covers touch-ups; a 5 HP piston handles full car paint jobs; for a paint booth running continuously, step up to a rotary screw compressor.

CFM with a 25–50% margin
29–45 psi at the gun
40-gallon (150 L) tank or more
Clean, dry air

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How many CFM does a spray gun use?

The number that matters most is not pressure — it is airflow (CFM). Every gun lists its consumption on the manufacturer data sheet; these are the typical ranges:

Tool	Typical consumption	Working pressure
Airbrush / touch-ups	1–2 CFM (28–57 L/min)	15–30 psi (1–2 bar)
LVLP spray gun	3.5–7 CFM (99–198 L/min)	10–25 psi (0.7–1.7 bar)
HVLP spray gun	9–15 CFM (255–425 L/min)	29 psi (2 bar) at inlet
Conventional spray gun	7–12 CFM (198–340 L/min)	35–45 psi (2.4–3 bar)
Pneumatic DA sander	10–13 CFM (283–368 L/min)	90 psi (6.2 bar)

The sizing rule: add up the consumption of the tools you will use at the same time and multiply by 1.25–1.5. That margin keeps the compressor from running at its limit, keeps pressure from dropping mid-pass, and keeps the motor from running non-stop. If you also sand with air tools, size for the sander — it consumes more than the gun.

What tank size do I need for painting?

Painting is a sustained demand: the gun draws air continuously through every pass. The tank is your buffer — it stabilizes pressure and gives the motor a rest. For occasional work, 30–40 gallons (100–150 L) is enough; for a shop that paints daily, 60–80 gallons (235–300 L) makes the difference between an even finish and a compressor that never rests. A piston compressor is designed to run in cycles (roughly 50–60% duty): if yours runs non-stop, it is undersized for your operation.

Piston or rotary screw compressor for painting?

Piston when you paint in sessions: body shops with moderate volume, woodworking, metalwork, touch-ups. Lowest investment, simplest maintenance, built for rough duty.

Rotary screw when the gun (or the booth) runs for hours: continuous airflow at constant pressure, no rest cycles, and far less noise. If your paint booth runs full shifts or several guns work at once, the jump to a screw compressor pays for itself in continuity and finish quality.

The silent enemy of a good finish: water and oil in the line

Most “fish eyes”, craters and blisters in paint are not the gun’s fault: they are moisture and oil traveling in the compressed air. Compressing air condenses water inside the tank and the line; without treatment, it ends up in your paint. The minimum setup for painting well:

Water separator pre-filter with auto-drain at the compressor outlet.
A micro-filter before the gun for particles and oil aerosols — see our air treatment line.
For booths and demanding finishes: a refrigerated air dryer, which reduces moisture across the whole line.
Drain the tank daily. It is free and extends the equipment’s life.

CBS recommendations by type of work

Touch-ups and small partsAir•co 2 HP Piston / 40 galAirflow: 9 CFM (255 L/min)
Tank: 40 gal · 125 psi (8.6 bar)View product

HVLP gun workshopAir•co 3 HP Piston / 62 galAirflow: 13 CFM (368 L/min)
Tank: 62 gal · 125 psi (8.6 bar)View product

Full car paint jobsCBS XV 5 HP Piston / 80 galAirflow: 22.38 CFM (633 L/min)
Tank: 80 gal · 175 psi (12 bar)View product

Paint booth, continuous dutyAir•co 10 HP Rotary ScrewAirflow: 30.02 CFM @ 145 psi
62 dB(A), continuous flowView product

The airflow figures listed are factory specifications for each model. Final selection depends on your tools and duty cycle: request a free technical consultation and we will size it with you.

Frequently asked questions

Can I paint a whole car with a 2 HP compressor?

Not recommended. A 2 HP unit delivers about 9 CFM and an HVLP gun consumes 9–15 CFM: the compressor cannot keep up, pressure drops mid-pass and the finish comes out uneven. For full cars, the realistic starting point is a 5 HP unit with an 80-gallon tank.

Why does my paint come out with water drops or “fish eyes”?

That is moisture or oil in the air line. Fix it with a water separator with auto-drain, a micro-filter before the gun and daily tank draining; in booths, add a refrigerated air dryer.

What pressure should I set on the regulator for painting?

Whatever your gun specifies: HVLP guns work around 29 psi (2 bar) at the inlet; conventional guns between 35 and 45 psi (2.4–3 bar). The compressor can generate much more — the regulator brings pressure down to the right point.

Does the compressor need to be oil-free for painting?

Not necessarily. A lubricated compressor with proper air treatment (separator + micro-filter) delivers air suitable for painting. Oil-free units are for processes that cannot tolerate any oil traces even with filtration, such as dental or laboratory applications.

Prefer us to size it for you? We are CBS Compresores: compressed air solutions since 1971, with spare parts, service and free technical advice across Mexico. Call our national line 800 611 1249 or contact us.