Hi, i have my kitchen hob gridle needs to be recoated as paint has worn off and there are areas were surface rust is becoming visible as time goes by. Material is believed to be cast iron. I need a diy approach to restore these painting them in black preferably paints being in aerosol cans which can resist direct flames for extended times. Which product would you suggest to do a good job and which is durable? Kindly advise and thanks in advance. Karl.