Yes you can recoat it. It is best if you heat it before recoating and just leave it sit in the oven till your ready so you don't get anything on it. You will want to respray them hot though.
I have brackets made for powder coating that clamp to my racks. I made them out of 3/8 fender washers, bolts, and rod. That way the part stays put with no swinging. I have had the best luck bringing the part up to 350F or 400F then remove the rack from the oven and set it on some saw horses to spray. Then I put it back in to cure. Repeat for second coat if wanted. I found that by spraying hot it allows me to put it on a little heavier if wanted, it gets less orange peal, and I miss less spots. Here is a couple picture of how I hang mine.
