Paints have varying levels of thickness, and those that have high levels of thickness may not be applied evenly by paint sprayers. Paint sprayers work by forcing paint to travel through a small tip to ensure that the spray of paint is even. This means that thick paint is required to be thinned to be used effectively in a paint sprayer. However, as paint that is far too thin is prone to streaking and running, it is important that you know how to use paint thinner correctly.
Safety first! Many paints, particularly oil-based ones, often emit fumes that you might accidentally inhale while spraying paint. To be as safe as possible, wear safety goggles and use a respirator.
Next, read the manufacturer’s instructions on the paint bottle label to work out which thinner should be used to ensure that the paint is thin enough. A general guide is to use water to thin latex paints and store-bought paint thinner or mineral spirits to thin oil-based paint. Many paints have a warning on their label that they cannot be thinned though, so check before you do anything.
First of all, you’ll need to strain your paint. The most experienced of painters often encounter the problem of clumps at the bottom of their paint cans even after applying an effective shaker. To use a store-bought paint strainer, firstly place it on a bucket, and then pour your paint through, just like a sieve (but without shaking the strainer).
Now, you’ll need to fill your paint sprayer’s reservoir and test the thickness of the paint. Grab a small test board and apply a limited amount of paint to it. Should your paint spray from the sprayer and form a very fine mist which eventually covers your test board without any streaking or running, you are fine to commence your painting project without thinning. Should the paint sprayer sputter paint or spray out the paint in a clumpy manner, it might be best to thin the paint first.
To do this, add paint thinner in small amounts to the paint bucket. To thin latex paint, you’ll need to add a certain amount of water in a certain ratio to each part of paint (check with your manufacturer). Stir until your paint is smooth.
Finally, if you are thinning oil-based paint, stir the recommended paint thinner into the paint at the ratio recommended by the manufacturer.