In the lazaret of wooden fishing boats we used Creosote, pine tar, and
Linseed oil, mix it altogether. Then we heated it up and painted it on.
When heating you have to be very careful because it ignites easily. It
wouldn't be good for a deck, but on the ground it would work alright.

Does anyone know a recipe for a wood preserative other then boiled
linseed oil and mineral spirits?