Latex vs. Oil Paints
The type paint you use will determine how well it will last and wear. Whether you use latex or oil-based, depends on the surface to be covered, the conditions it will face, and any base paint underneath. So, when you are making your paint type choice, consider these factors before deciding. There are other factors that will help you decide what type of paint to use as well, such the type of the surface you want to paint, its condition, age, and the type of paint previously used on the surface, if any.
When it comes right down to it you are making a choice between two different paint types: water-based latex paints; and solvent-based paints, which are referred to as oil-based paints or "alkyds."
So, what are the differences, or in other words why would you use one over another? Well the first and foremost difference is the make-up of the paint. The liquid portion of latex paint is water, while the liquid in oil-based paints consists of petroleum distillates and other organic solvents. About 75% of paints sold are Latex, but that does not mean latex paints are the best for your job. Let's look at when to use which:
Latex and oil-based paints have very different characteristics.
Oil-based Paints (We are assuming with the following you are using top-quality oil based paints)
Oil based paints have excellent adhesion, which is essential for a durable paint job. However, these paints also tend to oxidize and get brittle over time, which can lead to cracking in exterior applications, and yellowing and chipping in interior applications.
Oil-based paints are still your best choice if. you are repainting exterior surfaces with heavy "chalking"; and when repainting any exterior or interior surface that has four or more layers of old oil-based paint.
You should never use oil based paint on fresh masonry, or galvanized iron, or you will have a very quick failure of the paint.
Latex Paints (assuming a top quality latex paint)
Latex paints are easy to use and clean up, but they also offer significant performance advantages over oil based paints as well. They have greater durability, color retention, and chalk resistance, are less brittle and more elastic than oil-based paints, have better resistance to cracking, dry much faster, adhere extremely well to a variety of exterior surfaces, and have greater resistance to troublesome paint failures like blistering, flaking and peeling.
Latex paints should be used when painting any of the following exterior surfaces:
- wood, particularly in areas that experience freezing temperatures;
- new stucco and masonry;
- weathered aluminum siding.
You can also use quality latex paints on interior trim, and walls.
The following is an easy look comparison of some of the qualities of both paint types, assuming you use the same grade of paint:
Durability-
Oil based: excellent adhesion; and better adhesion than latex on heavily chalked surfaces. Latex: Excellent adhesion to most substrates; better elasticity than oil.
Color Retention-
Oil based: Not as good as latex, more likely to chalk and fade in sunny exposure.
Latex: Superior resistance to chalking and fading, especially when exposed to bright sun.
Ease Of Application-
Oil Based: More difficult to apply due to greater "drag," but goes on heavier for better one-coat hiding and coverage.
Latex: Goes on smoothly and evenly, with less brush drag.
Mildew Resistance-
Oil Based: Vegetable-oil base can provide nutrients for mildew growth; most products contain mildewcide to minimize growth.
Latex: Less likely to grow mildew; mildewcide additives discourage mildew growth, help maintain fresh appearance.
Versatility-
Oil Based: Can be used on most materials, but for new concrete, stucco and other masonry, a sealer or pre-treatment is required; should not be applied directly to galvanized metal.
Latex: Can be used on wood, concrete, stucco, brick, galvanized metal, vinyl siding, aluminum siding, etc.
Odor-
Oil Based: Stronger odor than latex.
Latex: Very little odor; non-combustible.
Cleanup-
Oil Based: Must use turpentine, paint thinner or other solvent.
Latex: Simple water cleanup.
Drying Time-
Oil Based: dries in 8 to 24 hours.
Latex: dries in 1 to 6 hours, making it easy to paint two coats of paint in a short time period.
