Electrolytic action on aluminum spars
I'm in the process of painting the aluminum mast, boom and cross trees on a 1978 Islander 28. I've removed all the standing rigging & other hardware and sanded down to bare metal which after 30 years is still in excellent condition but for some slight surface corrosion on the boom around some of the steel fittings. I believe this is the result of electrolytic action and I'm looking for advice to stop it recurring. I guess I can coat screws and pop rivets with silicone but what about other areas where steel touches aluminum? Is there a recommended insulating material, an insulating paint perhaps or perhaps just more silcone? Apart from this one question I am ready to finish the project as soon as we have the next couple of Seattle days that are dry and over 60 Fahrenheit. Thanks in advance, advice much appreciated.