You want your new outdoor bench to last for years. Or, your older wood bench is beginning to look plenty worn after just a few years of the changing weather conditions each season brings. New or old, help your outdoor wood bench stand up to the elements. For the old bench, start from scratch by removing any paint or varnish with a hand sander and 40-grit sandpaper. Now, treat the wood itself, whether the bench is new or old.
Rinse down the bench with a hose, and dry it off.
Pour a deck cleaning liquid that contains a brightening ingredient into a pump sprayer. Spray the bench from the bottom to the top. Use a brush to scrub the dirt off; use a small brush to get into small crevices. Hose it down again and let it dry.
Sand the bench gently with 100-grit sandpaper, just enough to even out loose grains, but not enough to remove the surface of the wood. Use an electric sander for most of the bench; sand small crevices by hand.
Wipe down the bench with a tack cloth, a slightly sticky cloth designed to remove all particles, dust, etc. before painting.
Apply gel stain with a small paintbrush to the sides and crevices -- coat flat surfaces with an applicator pad specifically designed for staining wood. Wait at least 24 hours before putting the bench outside or sitting on it.