This phenomenon is known as chalking.
Why does paint get chalky on aluminum siding.
Chalky surfaces will cause the paint not to adhere correctly to the surface and will cause premature peeling.
Why does chalking happen and what can you do about it.
Chalking due to oxidation is the paint s natural response to sunlight.
Before repainting an area with chalking paint it is necessary to remove all the chalk along with any dirt and dust on the paint surface.
If after two tries of hand scrubbing or power washing there is still chalk on the surface simply use a primer before repainting the aluminum siding.
This primer will cover up the chalk and allow the new paint to bond with the aluminum siding.
A dull chalky paint finish comes off when touched and makes a home s exterior paint job look dated.
This is called chalking and essentially is the existing paint breaking down from the weather.
One of the most important aspects of a paint job is the prep work.
One of the hardest surfaces to prep is a aluminum or vinyl siding that is chalky.
This oxidation that occurs on aluminum siding results in the build up of a chalk like substance on the siding itself which can easily be seen by wiping your hand across the aluminum.
This is a natural process.
If chalky paint is not removed it can eventually cause damage or discoloration to surrounding parts of the house.
When paint on outdoor surfaces ages it develops a light but noticeable buildup of powder.