Begin by removing dirt and any blistered or cracked paint with a paint scraper, scraping in line with the wood grain. Remove the paint down to the bare wood if you have to. Sand the edges of the area where you’ll be painting, first with medium-grain paper and then with fine-grain paper.
If the wood is extremely dirty-especially greasy or grimy from pollution- wash it with mild detergent such as TSP and let it dry thoroughly before you start to paint.
If water damage is a potential problem, apply water repellent, prime with an oil-based prime coat, and cover with two coats of high-quality paint.
Wait for clear, dry weather before you paint-temperatures between 50 and 90 degrees F. Wait until the dew has evaporated, and stop painting before evening dampness sets in. Don’t paint on windy or dusty days.
Wood surfaces must be clean, dry, and free of flaking or peeling paint before you repaint. Fix any damage and try to solve any structural problems that lead to water damage or you’ll be painting again before you know it.
Redwood, cedar, and cypress have the charm of natural color and texture. Instead of painting, you may prefer to seal these woods instead, to prevent natural resins from bleeding through the surface finish.