Spray Painting Furniture - the basics

Applying paint or other finish such as varnish, takes some practice to achieve a professional result. The best method of applying paint is the use of a spray gun. The spray technique can easily be mastered, provided that the right procedures are followed.

 How to spray paint.

Proper spraying techniques are very logical. Some of the basic principles for quality spraying are the following: 

Plan a systematic spraying routine that will reduce waste and overspray.  I start on the underside of a piece of furniture. On a chair for instance, tip it over and start with the legs and the bottom. Then turn it over and start from the top by spraying the back, armrests etc. Lastly spray the seat. Always work from top to bottom and the inside to the outside. Work from the less visible to the more visible areas. 

Make sure that you have adequate light. Keep the spray gun pointed perpendicular to the surface of the wood.  Avoid movements of the wrist. Move the whole arm from left to right.Set your gun to a fan pattern that covers the surface with the fewest passes and the least overspray.  Use a small fan pattern on edges, rails, turnings, and other narrow surfaces.  Use a wide fan pattern on large, wide surfaces.  

Start spraying about 4 -6 inches from the side of the wood, and move the spray onto the wood.  Keep moving at a uniform speed.

Keep the gun a uniform distance from the surface of the wood between 6 and 10 inches.  If you move it too close, you will make runs; move it too far away, and you will have dry spray.  You usually have to hold an HVLP gun several inches closer to the wood than you do a conventional gun. 

Finish your stroke several inches past the edge of the wood.  Make it a habit to release the trigger of the gun at the end of each stroke.  

Make sure that the strokes overlap to ensure even thickness. Also spray each stroke at least two times - one stroke to the edge and back on the same stroke. Overlap each previous stroke by half.  This will give an even thickness overall. 

Avoid spraying to much the first time around. Running of the paint may occur and then you will have to redo the whole process. Rather spray several coats to make sure you have adequate coverage.

Remember, practice makes perfect. Don’t expect to be an expert spray painter after the first couple of efforts.

First spray a test stroke on a piece of scrap to make sure the spray pattern is correct and the volume of air and material is adequate. After spraying a few strokes, stop spraying and stand away and have a look against the light to see if the painted surface is shiny and that it does not appear like a matt finish. If the latter is the case, not enough paint is deposited and it must be corrected by doing one of the following:

Make sure the paint is not too thick and the volume of air and paint release is sufficient.

Make sure the paint nozzle on the gun is open and not blocked by impuities.

Close the paint volume knob and spray to remove impurities. If this does not help, the cup must be emptied and the gun taken apart and cleaned.

 How to mix the paint

Another important skill that is required for proper spraying is the ability to properly mix the paint. In most cases the commercial paints are thick (especially water based paint) and need to be thinned to achieve a good flow of paint through the gun. Mixing takes a bit of practice. Water based paint can be thinned up to 10% or even more. A paint measuring cup clearly indicates the 10% scale and should preferably be used. A spray painter’s ruler can also be used. Always spray a test stroke to make sure that the right amount of paint is deposited.

Paint measuring cup

Most Acrylic paints must be thinned down to get the right consistency (thickness). Depending on the brand of paint you might have to do some experimenting to achieve the right consistency.

After thinning, the paint must be filtered through a paint strainer to remove impurities. There are different types of strainers but the most popular are nylon mesh or paper funnel strainers. 

Tip:

You can make your own reusable paint strainer from the same strainer material that can be bought from a paint dealer. Here is what you will need:

Fine mesh material (obtainable from paint dealers for 20 liter containers)

       Two empty 1 kg yogurt cups

       Utility knife

Take one yogurt cup and cut off the top part about 5 cm from the top.

Take the mesh material and cut out a circle of 20 cm diameter.

Place the mesh over the first cup and insert the cut-off top to hold the mesh firm.

The mesh is totally washable with water mineral spirits or thinners and can be used repeatedly.

As an alternative you can simply take a piece of elastic and secure the mesh over the empty cup.

  DIY paint strainer cup with mesh

DIY paint straining cup

I have been spray paintnig furniture for many years and in my book "How to spray paint furniture" I give details of issues such as the right spray tools to use, the best primers and paints to spray paint furniture, how to spray diferent types of wood and much more. You will also find many handy tips to
make spraying easier.