I am a new owner of a Hunter 1984, 34. shortly before I put the boat on the hard I noticed some white substance bubbling from around the rear keel bolt. Once I removed it I noticed that it seems to be caused by electrolysis. It stayed clean for a few days but when I put it on the hard I started seeing the bubbling action again. This boat has a SD steel keel. Any suggestions on how to stop this electrolysis? And how to clean the area that is already been affected? What is puzzling me is I have no sign of electrolysis on my zincs, or my prop. But significant signs of electrolysis on the rear keel at the bolt location. Thank you for any help you may have.