Linseed Oil

"Raw" linseed oil is just that... linseed oil squeezed from flax seed and packaged with no additional additives or preservatives. Raw linseed oil dries very slowly, taking weeks to fully cure. You should limit its use to the insides of wood gutters, chopping blocks, sawhorses, and other items exposed to the elements where drying time is not a consideration.

Slow drying is a mixed blessing. For oil-based paints, slow drying is a benefit, since this allows the paint to "level" itself, giving a smoother finish with fewer brush marks. The best looking paint jobs are invariably oil paint jobs, without question. However, when used as a wood preservative for items that are handled or walked on, such as tool handles, furniture, or wood decks, long drying times are undesirable.

"Boiled" linseed oil is not boiled. The actual boiling of some oils changes their drying characteristics. With linseed oil, though, it is the addition of certain solvents that causes linseed oil to dry more quickly, acting as if it were boiled. This makes it a better product for preserving tool handles, decks, and furniture.