If you're looking to repaint a deck or exterior surface, power washers are a great way to cut down on time and headache.
Unpainted Surfaces
If the surface has never been painted or is so weathered that it does not need to be stripped down, use a low-pressure washer (>1000 psi) to wash it and prep it for painting.
Most washers come with various nozzles that offer narrow or wide-angle washing. When working with wood, always use the widest angle possible, as it is the least abrasive and the least likely to raise the wood grain. Be sure to place the nozzle so that the water sprays at a perpendicular angle to the wood/paint grain — this arrangement maximizes paint removal while minimizing damage to the wood.
Painted surfaces
More often than not, the surface will need to be stripped down before being repainted. This is where pressure washers can really cut down on time and effort. If used improperly, however, pressure washers can cause more damage than good, so be sure to follow the steps below to correctly and efficiently get the job done.
- Cover all exposed surfaces with heavy duty plastic. When you use a pressure washer to remove paint, paint chips can fly in all different directions and plastic coverings can greatly cut down on clean-up time. Make sure the coverings are firmly affixed with weights or duct tape.
- Brush paint stripper onto the surface. Be sure to use rubber gloves, as stripping chemicals can cause burning and inflammation when exposed to skin. Cover the surface completely and liberally, and be sure to allow the prescribed time to elapse before gearing up the pressure washer.
- Brush paint stripper onto the surface. Be sure to use rubber gloves, as stripping chemicals can cause burning and inflammation when exposed to skin. Cover the surface completely and liberally, and be sure to allow the prescribed time to elapse before gearing up the pressure washer.
- Using a medium-pressure washer on wood surfaces may not be enough to completely remove the paint. DO NOT UPGRADE TO A HIGH-PRESSURE WASHER, as this will cause astronomical damage to the wood. Instead, wait for the wood to dry, reapply the paint stripper, and re-wash with a medium-pressure washer. You may have to do this several times to remove the paint completely.
- Regardless of your best efforts, you may still damage the top layer of wood (the grain will be raised and it will have a "fuzzy" appearance). After the wood has dried, use a power sander to gently remove the damaged wood and smooth it for painting.
- Some recommend not using a pressure washer at all on wood surfaces, and removing paint with sanding alone. This method will make your project time 3-4 times longer, will not be as effective in removing paint from crevices, and will probably result in a lot of back pain. Even if you have to sand a little after pressure washing, it is far more desirable than the alternative.
- Wait for the surface to dry COMPLETELY before painting (2-3 days for wood, 1-2 days for other surfaces). Apply 2-3 coats and be sure to allow adequate drying time between coats.
- Roll up your plastic coverings and voila! Your deck or exterior surface is good to go for the next 4-5 years.