Alkyd

Alkyd coatings are a class of cobalt is a deep blue purple color (iron driers are reddish orange) thus the colored driers are typically employed only in paint colors where the blue color of cobalt or reddish orange color of iron can be easily masked.

Alkyd coatings are produced in two processes; paint and varnish makers.

Alkyd coatings are typically sold in three classes; Long, Medium, and Short. These terms represent the relative fraction of drying oil component in the resin. Long oil alkyds have a high percentage of drying oil content and are generally sold as medium duty coatings for the consumer market. Medium oil alkyds have less drying oil and have a higher percentage of large molecular weight polyester backbone. They dry slower and are employed as high gloss coatings and wood finishes. At the bottom end are short oil alkyds where the percentage of drying oil is very low in relation to the base polyester polymer or backbone chain. These coatings will not air dry or harden unless heated. Short oil alkyds are employed as baking enamels for finished metal products.

Because the major components of an alkyd coating, i.e. fatty acids and triglyceride oils, are derived from low cost renewable resources this has kept the cost of alkyd coatings very low despite ever increasing cost of petroleum which is the predominant raw material source of most other coatings such as safflower oil, soybean oil, fish oil, corn oil, and tall oil (resinous oil by-product from pulp and paper manufacturing).