Can anyone reccomend a paint that will not allow the rust through my iron railings? What happens it that when it rains the bubbles of rain rest on the top and bottom flat parts of the railings where the bars go through and every year I have to keep re-painting them as the paint keeps bubbling and the railings subsequently start to rust under the paint too. I always get all the loose paint off and apply a good coat of Hammerite paint. Is there anything I can use that will reduce the need to keep painting them every year? Is there such a thing as a paint that gives a sort of plastic coating?