This chalking as you may know, is caused by the old paint oxidizing. The paint is breaking down due to weathering; UV, moisture, etc. Once the coating starts to chalk, it will continue to oxidize even though you wash it. The only way stop the oxidation is to cover the original paint with a new paint, preferrably an exterior acrylic. You are already one step ahead having washed it. The old paint provides a good base for the new paint to bond to. It may seem like a lot of work, but there is no easy way. A good paint sprayer works wonders.
A tip to prevent aluminum railings from chalking is to use a good car polish. The railings will always look like new.
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Bart Blainey, B.E.R.
Consultant/Journeyman Carpenter
Building Envelope Specialist
Master Renovator
provip@prodeck.org
http://www.prodeck.org
Barton Blainey (provip) specifically assumes no legal liability or responsibility for the accuracy, completeness or usefulness of any information or process disclosed. The above further expressly advises that any use of or reliance upon the information and or opinion disclosed is at your risk .
_________________________
Bart Blainey, B.E.R.
Consultant/Journeyman Carpenter
Building Envelope Specialist
Master Renovator
provip@prodeck.org
http://www.prodeck.orgBarton Blainey (provip) specifically assumes no legal liability or responsibility for the accuracy, completeness or usefulness of any information or process disclosed. The above further expressly advises that any use of or reliance upon the information and or opinion disclosed is at your risk .