You can scrub it with a wire brush or use a power washer to make the job easier.
How to paint vinyl siding trim.
Primers for aluminum or vinyl siding.
Start by cleaning your siding of any mildew dirt or debris.
Then you can apply the paint.
Use a paintable acrylic caulk not silicone for aluminum or vinyl siding.
Use a brush small trim paint roller or a paint sprayer if you prefer.
If using a pressure washer or hose do not force water behind the vinyl panels.
Do not caulk under the laps of the siding you want to allow for expansion and contraction of the siding.
Apply a smooth even coat of a latex exterior primer onto the vinyl trim.
Open the latex paint and mix it well.
Use a general purpose cleaner and make sure the surface is dry before applying paint or primer.
Be careful when smoothing the caulk with your finger especially on aluminum siding the edges can be very sharp.
Use the sprayer to coat the surface taking care to apply the paint evenly.
If the vinyl is peeling and cracked a primer should be applied first.
It is perfectly acceptable to use a paint sprayer to apply 100 acrylic paint.
Pour a small amount into a hand held container.
First and most important confirm that painting the siding won t void its warranty if the warranty is still active.
Choose the proper paint latex urethane formulated for outdoor use.
Work only in suitable weather.
Begin painting the vinyl trim at the highest point starting at one end and working your way across in long even strokes.
Prepare the vinyl surface by cleaning it thoroughly.
Also there are some rules and limitations to follow when painting vinyl siding.
Let the primer dry according to the manufacturer s.
Avoid hot humid or windy days.