A retired paint manufacturer told me he used to make a special linseed oil based paint for six beekeepers in the Queenbeyan area. He says you can make a good approximation by adding 500ml of Raw Linseed Oil ( can get it at Bunnings Paint Department) to 2 to 3 litres of gloss enamel(oil) based paint. Apply to bare timber (no primer or undercoat)- allow to dry and add a second coat. It will take a little longer to dry than solvent based paint. The oil is absorbed into the wood and preserves it a lot better than regular paint.