Natural oil finishes are a traditional way of treating floors, decks and wood furniture. Teak oil is found in the trunks of teak trees and is known for its rich colour. Linseed oil is pressed from dried flaxseed and then heated and treated with chemicals. The benefits of teak and linseed oils are numerous, but there are a few differences that will influence which one you choose to use for your project.
Linseed oil is slow drying, so it retains some flexibility for a while. Also, if it is not dried properly, it can be sticky. Linseed oil requires at least a couple of days to dry sufficiently before adding a second coat (which is recommended). Teak oil dries within 12 to 24 hours. It must be waxed to maintain durability but does leave a lustrous finish that lasts. Teak oil dries fast to a hard finish and does not get sticky. Teak oil is absorbed by most types of wood and leaves a more natural finish. Linseed oil darkens the colour of the wood considerably more than teak oil will, but drips or "globs" of either oil will leave a stain.
Linseed oil and teak oil penetrate most woods well. Teak weathers over time, especially if used outside, and must be reapplied at least once a year. Linseed oil keeps its finish longer than teak, but removing it from wood furniture or floors in order to refinish is difficult. Teak dries hard and stays that way and is easily scraped off and recoated.
Linseed oil is recommended for use on indoor flooring and wood furniture. It does have preservative properties, but it doesn't protect from sun damage. The long drying time makes it difficult to use on outdoor projects such as wood decks or outdoor furniture. Linseed is used in linoleum, because of its durability and flexibility, and makes an ideal interior floor finish.
Teak oil is recommended for outdoor wood decks and furniture because it seals hard and protects wood from the elements. It dries relatively fast, but its hard finish can crack and chip over time. Teak oil can be used indoors, but because of teak oil's necessary maintenance, it is used more often in outdoor applications.
Teak oil is derived from natural wood, but is toxic if ingested. Boiled linseed is not actually boiled. It is mixed with solvents like chromium, arsenic and cadmium, and is also toxic. Boiled linseed is also combustible, so rags should be stored in water in a metal container or they should be washed. Both oils should be used in a well-ventilated area.