What kind of finish should be used on mahogany deck furniture?
Greg Williams: Since your primary consideration is exterior durability, (resistance to UV, weathering, abrasion, and impact) an exterior rated polyurethane will be the best choice for most purposes. If you have professional finishing equipment and experience, you might choose a linear polyurethane such as Awlgrip Clear. Be prepared for sticker shock, as these are very, very expensive. For the average (or better) deck furniture, the brush-on consumer grade polyurethane, renewed every few years, will be satisfactory.