Had a very small leak in the bow of my bayrunner, had it patched up but noticed lots of white corrosion spots on the bow area of the hull. The boat has no grounds to the hull and has not ever leaked until now. Will these spots continue to eat through the hull or is this fairly normal for theses older aluminum hulls? I have zincs on the transom area and wash the boat well after each use. Any advice would be greatly appreciated.