The function of the tools I use and how they work are explained here. Specific tools used are noted in bold.
The doors are first sealed with a thin penetrating epoxy sealer. This soaks well into the wood, providing protection from elements and a bonding surface for the top coat. When dry, the sealer is light sanded, as are the intermediate top coats. The top coat varnish and paint are sprayed on using an HVLP sprayer.