Just as a fresh coat of paint can enliven a home's interior, a new coat of exterior paint gives your home an inexpensive facelift and increased curb appeal. Whether you're painting a home's clapboard siding, a porch, or even old wooden window frames, the preparation is key in obtaining attractive and long-lasting results. Here's how to approach your exterior wood painting project:
Remove any old peeling paint from the surface to be painted. Using a putty knife or scraper is a rather laborious, but effective way to do this. Remove as much of the loose paint as possible, and remember that paint that has lost its adhesion qualities is losing its bond with the wood surface and that simply painting over it will come back to haunt you down the road.
Wash the scraped area with a mild detergent and a scrubbing brush and then rinse thoroughly. Then, check the areas that you just scraped to see if the washing has loosened any more of the old paint. Chances are that it will have, so take out the scraper and remove as much of the remaining loose and peeling paint as possible. This is tedious work, but making the effort here will pay off in the long run.
Use a medium-grit sandpaper to rough up the areas where any of the old existing paint remains. This will at least take off the sheen of the paint, allowing for better adhesion when you repaint. Pay particular attention to the areas where this old paint meets bare wood. You should feather these edges for a nice smooth appearance.
Wash the entire surface once more. The surface should be as clean as possible, so use the scrubbing brush and soapy water to remove all debris, grease and dirt from the wood. You may also need to use bleach on the wood if there is mould and mildew present. Either way, after the surface is completely scrubbed clean, rinse with clean water and allow to dry. Wood is quite porous, so it's best to wait for at least two days before proceeding to the next step.
Apply an exterior primer to the wood surface. If it's a large area, you can use a paint sprayer rather than a brush to do this. Either way, make sure you prime all exposed areas of the wood. Any areas you miss will be susceptible to rot and will be the places that blister and peel first. If you see any exposed nails or screws in the wood, countersink them and cover the holes with an exterior spackle. Allow the primer to dry per the instructions on the can.
Apply the exterior paint to the wood surface. Opinions vary on the relative merits of acrylic and oil-based paints, but acrylics tend to be more flexible and less prone to splitting and cracking than oil-based paints, since they're more able to move with the wood as it swells and contracts in changing weather. Check the manufacturer's recommendations for drying times, and then apply a second coat.
Oil-based primers are worth considering because of their wood-penetrating capabilities. This gives a better seal to the wood. Don't be afraid to try new colours when repainting the exterior of your home. Sticking with a traditional white is fine, but experimenting with bold new colour choices can take the appearance of your house to a whole new level. See link below for tips on choosing new colours.
If you're going to be sanding wood on an old house and you're unsure about the paint's history, make sure you invest in a lead paint testing kit. Sanding old paint containing lead will generate toxic dust. Even if the paint is lead-free, it's a good idea to wear a dust mask while sanding.