Should I Use Oil or Latex Paint?
Oil-based paint (aka alkyd) is used much less frequently than in the
past. Improvements in the durability of latex paints (aka acrylic), combined
with their other qualities and convenience make them the most popular
choice by far.
The fundamental difference between latex and oil paints is the use
of different carriers and binders. The carrier is the liquid that evaporates,
leaving behind a layer of binder and pigment. In latex paint the carrier
is typically water with glycols or glycol ethers as a solvent. In oil-based
paints, the carrier is a formulation of mineral spirits and petrochemical
The binder is the material that adheres to the painted surface. In
water-based paints, it is formulated from acrylic resins, polyvinyl acetate
and styrene butadiene. In oil-based products, binders include petroleum
based alkyds, polyurethane's and silicones. Natural oils can be used,
including linseed, tung and cottonseed oils.
Ease of Use
The award goes to...latex. The ease of clean-up with water is almost
enough on its own to justify choosing latex for ease of use. In addition
the ease of spreading and the low odor, make it easier to work with than
Oil-based paint requires thinners to clean hands, spills, tools and
brushes. The paint thinner then has to be disposed of in an appropriate
manner. Oil paint is thick and sticky, requiring a little more effort
to apply. Oil-based paints have a strong odor and the odor can last days
or even weeks if you have a sensitive sniffer.
This has always been oil's strong point. It has a hard, durable finish.
So hard in fact, it should not be painted over latex, because the softer
coat beneath tends to flex and then crack the oil coat. Oil dries to
a hard smooth finish and withstands abrasion well. Oil continues to dry
over its entire lifetime, and eventually, if repeatedly recoated,
Latex however, is flexible and expands and contracts with the surface.
Furthermore, latex's porosity allows moisture to escape from the painted
surface (a good thing). As a result of improvements in the formulation
of latex paints, their durability now rivals oil, or even exceeds it.
Their are different qualities of latex and the best is pure acrylic.
One hundred percent acrylic paint costs more, but it should last longer
than cheaper varieties and ultimately save you money in the long run.
Latex-based paint is more resistant to fading, yellowing, cracking and
chalking than oil paint. It resists mildew better and the best 100%
acrylic paints resist abrasion. Most people can't tell the difference
between oil and latex when they look at it, even
professionals sometimes have to test the paint to be sure which it is.
In an unscientific test, I painted two wooden panels of beadboard.
I used the same color, but I painted one with primer and oil and the
other with primer and latex. I let them dry, and then compared them without
knowing which panel was which. I preferred the oil painted panel because
it had a warmer appearance. The texture of the paint was smooth and even
like glass. It resembled powder-coated metal. The latex panel looked
fine, but the surface was less smooth and did not have the warmth. Even
though the same color was used, they were different paints and so the
sheen may not have matched as closely. My observations of the two panels
may have something to do with sheen rather than the paint itself. In
any case, I used oil paint for the beadboard wainscoting in my bathroom.
Latex is faster drying. On the down side, it is not as effective at
blocking stains from showing through. Latex is more temperature sensitive
and has narrower acceptable conditions for applying paint. The biggest
negative is that it does not adhere as well as oil paint. However, with
proper surface preparation, adhesion should not be a problem.
Another point to consider, what kind of paint are you painting over?
It is always safest to go over old paint with a fresh coat of the same
type. It is generally considered acceptable to go over oil paint with
latex, but proper surface prep is essential. In some rare cases, latex
can actually pull multiple coats of old oil paint right off the wall.
Painting oil paint over latex is possible but inadvisable. The oil should
adhere to the latex, but the flexibility of latex will ultimately lead
to cracking of the oil paint.
It used to be that the binders in oil paint gave it the edge in durability.
Nowadays, the binders in latex paint have caught up with or surpassed
oil. In consideration of latex's other qualities, it now is the right
choice in most cases. Many professionals will disagree and swear by oil-based
paint. To be fair, it has some virtues, and in some cases may be the
better choice. However, the debate may become irrelevant as oil-based
paint becomes more and more legislated out of existence.