I just finished a 250 rf and painted rust oleum flat black paint on it. My firebox is 3/8" thick. Ive cooked on it 3 times now and there are a few spots on the firebox where the pain is flaking off and the front of the firebox is showing some rust . If i apply some high heat paint will i have to strip all paint on there now off or can i go over it? And has anybody had good luck with the high heat paint?