The third step to fixing your peeling paint issues is to patch any small issues with an exterior spackling compound. For larger problem areas, use a two-part polyester resin filler to repair any holes or damaged wood. Mix the filler as directed and apply with a plastic squeegee. Sand the cured filler with a hand sander to make it smooth and level with the surrounding wood.
Paint tends to peel or flake near joints between dissimilar materials — think siding and trim, window frames and glass, etc. This is where water seeps into cracks and soaks into the wood, causing the paint to peel. Use an old screwdriver or similar tool to scrape out any failed caulk from joints and cracks. Then use a stiff brush to clean the joint. Allow any moisture to dry completely before applying exterior paintable caulk with a caulking gun.
Don’t caulk the horizontal joints between siding panels or the vertical joints between members in the same panel. These joints permit moisture behind the siding to escape.
Clean and wash the surface before painting. Rent or buy a pressure washer to thoroughly clean your home’s exterior. If mildew is present (black or gray spots), you’ll need to remove it by washing the surface with a mixture of Trisodium Phosphate (TSP), bleach and a stiff brush. Wash from the bottom to the top to avoid staining. Allow the surface to dry for at least two to three days before painting.
Use TSP as directed by the manufacturer. TSP can corrode metal and damage finished wood. Be sure to wear protective eyewear, clothing and rubber gloves.
A pressure washer can also be very helpful in removing loose paint. If you use it for early prep stages, however, you'll still need to wash off the sanding dust at this stage.
Remove light fixtures and other hardware with a screwdriver so you don’t have to paint around them. If you can’t remove a fixture, you can cover it with plastic sheeting and masking tape. Remove the shutters so you can paint behind them — you can save the chore of painting shutters for a rainy day in the garage. Also, cover shrubs, the ground and walkways with drop cloths. Slide window screens up behind storm windows or remove them.
Don't mask until the last minute, and remove masking tape shortly after you complete painting an area.
Paint will not bond well to wood exposed by sanding. Make sure to use a high-quality paint primer, like True Value WeatherAll® Ultra Premium exterior primer/sealer, before you paint. This seals porous surface material so your topcoat won't soak in and dry unevenly. Priming also helps prevent peeling, rusting and bleed-through (especially on wood and concrete). Apply with a brush, roller or spray applicator to all bare wood. Allow it to dry completely before moving on to the next step.