Things You'll Need
Green wood sealer
"Green wood" refers to any wood surface that is freshly cut and still relatively moist. Lumber purchased at a lumberyard or hardware store is almost always dried or treated wood. If you're using your own fresh-cut green wood, products designed for dried wood won't work well on the surface. Fortunately, there are specialty products available to help you paint on green wood. With just a little prep work, you can paint right away, avoiding a lengthy wait during the wood's drying period.
Sand any overly rough spots with 150-grit sandpaper. Fresh paint won't erase visible imperfections, but sanding will smooth them out for a better painted finish.
Wipe off dust from sanding with a damp rag.
Apply green wood sealer to the wood's cut ends using a paintbrush. Green wood sealer is designed to prevent splitting as the green wood dries. While it doesn't hurt to apply the sealer to the entire piece of lumber, the cut ends the most crucial part of the cut green timber. Green wood sealer is available at most hardware stores. Wait for the wood sealer to dry.
Prime the green wood with stain-blocking primer and a paintbrush or paint roller. As the green wood dries and ages, it releases natural oils that can discolor paint. Stain-blocking primer prevents these blemishes. Stain-blocking primer is available at many hardware stores and some artist supply stores. Wait for the primer to dry.
Paint the green wood with oil-based paint. Use a paintbrush for small spaces and a paint roller on larger wooden surfaces.
Apply a second coat after the first coat dries. Do not use the freshly painted green wood item for 24 hours. While oil paint dries in just a few hours, it doesn't cure for an entire day.