A pressure washer or even taking the chairs to a car wash for a professional washing is also helpful in the event that none of the methods mentioned above work.
Car wax on resin furniture.
Resin on furniture is non pigmented paint.
An appropriate amount needs to be applied on the chairs and then buffed so no residue remains.
Patio furniture is always exposed to the elements.
Another useful and highly effective way to clean resin chairs is by car wax.
Meguiar s was founded on furniture wax.
There used to be waxes for resin furniture but if you can t find them use a car wax.
Oxidation commonly occurs on outdoor furniture such as resin plastic chairs and is caused from prolonged exposure to the sun.
Using wax on resin can make a real mess and take a long time to buff out with all the little nooks and crannies.
It may also make the furniture too slippery and cause someone to slip right out of a chair.
Sunshield should be used regularly or whenever outdoor furniture looks faded or dry.
So use what ever you have.
This distinctively blended product effectively penetrates and replenishes natural oils.
I would pick a carnauba based wax just for the hardness.
It can happen to almost any material that is left in the sun for long periods of time including aluminum fiberglass and even car paint.
You might want to give it a light hand sanding just to smooth it out and or apply a wax.
Applying occasional coats of boat or car wax to the chairs will protect them from future oxidation.
I would stay away from using wax.