There are three ways to clean the siding.
Best way to clean aluminum siding for painting.
There are many ways to make homemade aluminum siding cleaner from scrubbing with cream of tartar to lemons.
You need to scrape off peeling and flaking paint and then chisel out any old caulk lines and apply new ones.
Add in a few stalks of rhubarb tomatoes or lemons and boil the mixture.
Use the directions on the tsp package to mix the cleaner correctly.
Scrubbing with a sponge using a pressure washer or a random orbit sander.
As long as the siding is clean you won t need to use a primer unless raw metal is exposed.
You can use a cleaner specially designed for aluminum siding but a mixture of trisodium phosphate tsp and water works just as well.
It s best to use a power washer angling the spray in the direction rain would hit the house as washing from the bottom up can cause unnecessary damage to the siding.
You can add a cup of chlorine bleach to the mixture if your siding also has mildew on it.
Scrub with a sponge soak abrasive sponge in cleaning solution and scrub siding clean.
However you can also use rhubarb or tomatoes to clean aluminum siding.
There s still more preparation to address before painting aluminum siding.
The best way to get this siding clean is to power wash it.
For any of these cleaning solutions fill a bucket with water from your garden hose.