Everyone knows that oil and water don’t mix.   The viscosity and chemical properties of oil and water are so dissimilar as to make combining them impossible.    If you pour a cup of oil in to a pot of water, the oil will sit on top of the water rather then dissolve into it.  The differences between the two continue in to the world of professional painting.   It used to be that most paint was either water-based or oil-based so understanding the practical applications of each was vital to selecting the right paint and doing a good job.   Now, understanding the llegacy of oil-based paint is important for different reasons: new products have been developed that have rendered oil-based paint nearly obsolete.   Knowing what made oil-based paint useful is important when seeking a product that replicates that utility just as understanding why oil-based paint has fallen out of favor is key to seeing the future of professional paint products.

A can of oil-based paint. Image courtesy of UTNE.

New developments in paint chemistry have led to water-based paints and acrylic paint products that mimic the characteristics of oil-based paints.  The Environmental Protection Agency (EPA) continues to crack down on paint products that include high levels of volatile organic compounds… including oil-based paint.  As a result, many paint manufacturers have created water-based products that behave like oil-based paints without angering the EPA.   Furthermore, acrylic paints have been developed that surpass oil-based paints in quality while not requiring such extensive time to dry.  Put more directly: painters using oil-based paints are living in the past.  New water-based products and acrylics can offer all of the good properties of oil-based paints at a lower cost and in a way that is safer for the planet and the painter themselves.

As it is now, acrylic paints and latex paints are being developed in new ways and, combined with water-based paint, have all but rendered oil-based paint obsolete.   Regardless, every paint professional should understand the difference between oil-based paint and water-based paint if only to be able to educate and counsel clients when planning a project.

Here are some of the key points of comparison between water-based paint and oil-based paint, as well as information about new alternatives available to the modern paint professional.

Drying time:

Water-based paint dries quickly, which can allow the painter to apply multiple coats in the same day. Conversely, oil-based paints take a substantially longer time to dry then their water-based counterparts.  Some professional painters long viewed this as an advantage; a longer drying time meant the paint has more time to find smooth out and find its level which can help hide brush strokes.  New acrylic paints are available that are designed to dry slowly and replicate the smooth leveling quality of oil-based paints.

Cleaning oil-based paint off brushes. Image courtesy of Addicted to Decorating

Cleaning:

Water-based paint is significantly easier to clean than oil-based paint.  Brushes tend to have a longer lifetime if they are used with water-based paint and stray drips and drops can be cleaned thoroughly with a cloth and water.  Oil-based paint can only be cleaned using turpentine, mineral spirits, or paint thinner.   Properly cleaning brushes is not as simple as simply placing them under running water and flexing the bristles of the brush; to clean oil based paint properly off of a brush takes more time.  Now, water-based paints that have the same protective strength and high sheen of oil-based paint are available on the market.  This blends the best of both worlds: easy to clean but quick drying without brush strokes.

Substrate Protection:

Oil-based paint provides a more robust protection to the surface beneath it then water based paint.  Water-based paint is more likely to absorb in the surface due to its thinner consistency.   Oil-based paint creates a layer on top of the substrate that not only offers increased protection, but is also easier to clean.  Fortunately, paint manufacturers are incorporating new additives’]);” href=”http://www.byk.com/en/additives.html”>new additives from companies like BYK  in to their products to enhance the protective qualities of water-based paint and acrylics.  These additives allow water-based and acrylic paints to offer substrate protection similar to oil-based alternatives.

Additives available for the professional painter. Image courtesy of BYK.

As a professional painter you likely already know these core differences between oil-based paint and water-based paint.   For practical purposes, choosing which is the option for your job may seem obvious.  That said, if you are still using oil-based paint then you are likely using a more expensive, inferior product.   Click here to learn more about the fascinating innovation taking place in paint chemistry.