Boiled linseed oil is relatively effective as a wood sealer, but there are better products available. Boiled linseed oil effectively acts as a wood preservative and takes far less time to try than raw or untreated linseed oil.
There are a few drawbacks associated with linseed oil. It requires thin, multiple coats and each coat must thoroughly dry before application of the next coat. If not applied properly, the multiple layers can become gummy and difficult to remove.
Linseed oil does not provide protection against ultra violet rays, which is one of the main causes of damage to untreated wood and exposes it to insects, mildew and fungi. Also, as an organic food oil, linseed oil does not inhibit the growth of mold. It also does not harden so it is not recommended for sealing floors and decks.