ALKYD & OIL-BASED PAINT
JILLIAN SZACHURY
Alkyd or oil-based paint is produced using a chemical as a solvent. Chemical solvents can come in two forms, for which we know as hydrocarbons or oxygenated. Hydrocarbon solvents include ingredients like naphtha, mineral spirits, toluene, and xylene. Oxygenated solvents on the other hand include ingredients like ketones and alcohols. Both of these solvents make the mixture of binder and pigments fluid to the point where it is able to spread over a specific surface. As the solvent evaporates with time, the mixture is cured by oxidation, making the mixture extra hard.
Figure 1: Alkyd and oil-based paint comes in a variety of colors, being able to be utilized on a variety of different surfaces, and in different styles of interiors and exteriors.
There are a lot of characteristics that both alkyd and oil based paints obtain. For example, solvent based paints like alkyd and oil paints take a longer time to dry compared to other types of paints, where it can often take up to 48 hours for the paint to dry completely, and a solid 5 days for the paint to give off a hard, glossy finish that is simply unmatched to latex paints. The more alkyd or oil the paint contains, the longer it will take for the paint to dry. Although the drying process is longer for alkyd and oil-based paints, we come to find it being very well worth it, due to its sustainability and life cycle costs. Alkyd and oil-based paints are very well known for its elasticity, where these paints can last a very long time, and has a less likely chance of cracking overtime compared to other types of paints.
Alkyd paints provide a hard glossy surface that is good for windows that need to slide easily, as well as cabinets and furniture too. Oil-based paint can be used on almost all surfaces too, and is praised for its high durability and rich finish. However, one must be cautious with oil-based paint, where this type of paint has poor indoor air quality. Oil paint releases strong fumes into the air that can be overwhelming, where VOCs included in the making of this paint can be very harmful to breathe in. This type of paint is also very difficult to wash, and cannot be washed with water. If you choose oil paint, the maintenance requirements for this type of paint is difficult, but very much worth it in the end.
Oil paint is the most complicated of all paints from a materials point of view when it comes to the durability of the paint. The process of applying alkyd and oil paint can be roughly divided into three steps in order to maintain its glossy, rich finish:
1. Preparing the ground - All bases need specific treatment prior to applying oil paint to the specific surface. A material like gesso ensures good preparation before applying oil-based paints to a surface.
2. Applying the paint - There are in theory two oil painting techniques: alla prima (wet-into-wet) and layered painting (paint is layered once the layer before is completely dry).
3. Applying the varnish - Varnishes for oil paints generally consist of resin dissolved in a solvent. They protect the paint layer and determine the gloss of the work.
Figure 3: Alkyd paint is oftentimes used on cabinetry, similar to how it is utilized in this space on the kitchen island, bringing bright, invigorating colors into the space.
The ASTM Standards for paint are quite simple, and stated on their website. A few testing examples include:
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D2245 Test Method for Identification of Oils and Oil Acids in Solvent-Reducible Paints
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D2369 Test Method for Volatile Content of Coatings
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D2689 Practices for Testing Alkyd Resins
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D4236 Practice for Labeling Art Materials for Chronic Health Hazards
Figure 4: Designers now are using interior doors to introduce unexpected accent colors that add impact to a room with oil based paint.
Aside from ATSM, there are other organizations that test alkyd and oil-based paints, which are listed below:
KTA's Coating Laboratory
Society for Protective Coatings
American Coatings Association
Avomeen
Stolk Laboratory