You must clean powder-coated aluminium surfaces because things such as dust, dirt, grime, and foreign matter will absorb moisture and damage the coating. Use a wet sponge with clean water and a small amount of mild detergent. Make sure you thoroughly wash off the detergent with more clean water to avoid deterioration of the coating which will occur as a result of soap deposition.
Never use abrasive cleaning agents such as Ajax and, if small scratches occur, they can be easily buffed out with a good quality car polish. If you do attempt this yourself, use the polish carefully, ensuring the coated surface is not removed.