How do you use a paint sprayer for woodwork?
Do it yourself · Finishing
FinishingWorking with a paint sprayer
A sprayer is faster than a brush and leaves a smoother coat. It is far less forgiving, though: any mistake in the settings shows up across the whole surface at once.
- Always test-spray first
- 20 to 25 cm distance
- 50 per cent overlap
When a sprayer pays off
You won't get the sprayer out for a single door. For six doors, a kitchen unit or a set of slats, you will.
The gain from spraying lies in two things: speed over large surfaces, and no brush marks. On a flat door or a set of cabinet doors, that gives a result you simply cannot achieve with a brush. On a single skirting board or a stair handrail, you lose more time masking and cleaning than you gain.
The second point is preparation. A sprayer atomises paint in every direction, including where you don't want it. Everything within a few metres has to be covered, and indoor work also calls for ventilation and a dust mask. Expect to spend more time masking than spraying.
And then there are the settings. Thinning, air pressure and the nozzle opening together decide whether you get a mist or a jet. You adjust that on a piece of cardboard, not on your workpiece — and again every time you use a different product.
Take a piece of cardboard or scrap wood and spray a pass. If you see drips or runs, the paint is too thin or you are moving too slowly. If you see a grainy, rough surface, it is too thick or you are holding the sprayer too far away. Adjust until the pass is smooth and even.
- Distance to the workpiece
- about 20 to 25 cm, kept constant
- Movement
- parallel to the surface, not swinging from the wrist
- Overlap
- each pass about halfway over the previous one
- Starting and stopping
- beside the workpiece, not on it
- Thinning
- as stated on the tin; test on cardboard
- Number of layers
- several thin coats instead of one thick one
- Cleaning
- immediately after use, or the sprayer is ruined
To be fair: a paint sprayer costs you in preparation and clean-up what it saves in spraying time. Masking, thinning, test-spraying and above all cleaning add up to more than an hour. With fewer than four or five surfaces, a foam roller and laying off wet-on-wet will get you done faster and more cheaply.
Adjusting the sprayer
- Strain the paintPour the paint through a fine strainer into the cup. A single grain of dried paint will block the nozzle in the middle of a pass.
- Thin as instructedEvery paint has its own thinning percentage for spraying. Too thick gives orange peel, too thin gives runs.
- Choose the spray patternMost sprayers can atomise horizontally, vertically or in a round pattern. Set the fan at right angles to the direction you are moving in.
- Set the flow rateStart low and turn it up until the pass just covers. More material almost always means more runs.
- Test-sprayOn cardboard, in the same position you will use on the workpiece. Only then do you move on to the real work.
In pictures · Four movements that decide everything
Schematic drawing.
Four movements that decide everything
Constant distance
Move your whole arm parallel to the surface. If you swing from the wrist, the middle of the pass will be thicker than the ends.
Start beside the surface
Pull the trigger before you reach the workpiece and release it after you have passed it. That way you won't get a thick spot at the start of every pass.
Fifty per cent overlap
Let each pass fall halfway over the previous one. It seems a lot, but it is what gives an even coat.
Order on a door
First the edges and mouldings, then the flat areas. That way the last movement covers the largest surface and you won't see any lap marks.
| What you see | Cause | Solution |
|---|---|---|
| Runs | too much material, too close, or too slow | less material, further away, move faster |
| Orange peel | paint too thick or too little pressure | thin it better, increase the pressure |
| Dry, grainy mist | too far from the surface or too fast | closer and slower |
| Stripes between passes | too little overlap | each pass halfway over the previous one |
| Spatter | dirty or damaged nozzle | clean it, and replace it if it has burrs |
Cleaning decides whether you can spray a second time
A paint sprayer left standing for an hour with paint in it is usually lost. Dried paint in the nozzle and the air channels rarely comes out completely, and a sprayer that is no longer clean will never give an even mist again.
- Leftover paint back in the tinDon't throw away what you can still use, but strain it again if you keep it.
- Flush throughFill the cup with water for water-based paint or with the right solvent, and spray until clear liquid comes out.
- Take it apartRemove the nozzle, needle and air cap. This is where the paint collects, and flushing alone won't reach it.
- Brush gentlyUse the brush supplied, never a wire brush or a pin: one scratch in the nozzle and the spray pattern is permanently skewed.
- Dry and lightly greaseLet everything dry before you put it away; the needle gets a drop of suitable oil.
Frequently asked questions about working with a paint sprayer
How far away should I hold the sprayer?
About 20 to 25 centimetres, and you keep that distance constant by moving your whole arm instead of swinging from the wrist.
Why do I get runs?
Too much material, too close to the surface or moving too slowly. Usually all three at once. Turn the material flow down and move more briskly.
What is orange peel and how do I prevent it?
A grainy texture caused by paint that is too thick or pressure that is too low to atomise it properly. Thin as instructed and increase the pressure.
Do I need to thin paint for spraying?
Almost always. The tin states a thinning percentage for spray application. Then test on cardboard before you start on the workpiece.
Is a sprayer better than a brush?
On large flat surfaces, yes: smoother and faster. On small or complex pieces, you lose more time masking and cleaning than you gain.
How soon should I clean the sprayer?
Straight away. A sprayer left with paint in it for an hour usually can't be saved — and a half-clean sprayer will never spray evenly again.
Or with a brush after all?
For a single door or one piece of furniture, laying off wet-on-wet is faster and easier.
Have a question about your project? Just ask — we're happy to help.
Photo via Wikimedia Commons: HVLP spray gun with paint cup, ready for use — Cpl. Salvador Moreno, Public domain