While there are many different types of wood treating and applications, our team has many years of experience in assisting our wood treating customers by supplying different types of oil to treat their wood for moisture prevention, while also keeping their wood a dark color. This has proven to be a very difficult achievement, but we have perfected the process. Contact us for more info!Mineral spirits makes more sense than diesel fuel oil. The beading would be the paraffin wax mixed into the mineral spirits. Boiled linseed oil also was used when applied to wood. Diesel could have been used as the carrier but that was usually an outdoor application. Penta was added for good wood protection from decay.