I think Jay Hansen has been having those powder-coated. I've used Redkote in my Mac 125 fuel tanks and it works pretty well. Saw-King recommended Kreem as another
liquid fuel tank sealant. I've used both Kreem and Redkote and found Redkote easier to work with. Kreem is good but requires that your tank be very clean. If there are any
residues of any kind, Kreem won't stick good.