Blackeya,

Sorry to put a damper on things, powder coating is classed as a decorative finish and doesn't stand up to well to salt and continual exposure to the weather, you'll need to maintain the finish by keeping it clean. If you hadn't been wanting a satin black finish a solution would have been to ask the powder coater to apply a coat of clear powder. This however normally gives a deep gloss finish unless of course he has a satin powder. If you look at alloys some are wet painted, some are powdered. The powder finish always has clear powder applied to protect the silver powder, which is made from polyester.