Electrolysis question

[Go Harley]

I've got a 17½' Alumaweld Stryker with a Merc 65 Jet. I've used it in the salt a few times, then dipped it in a freshwater lake to flush the salt out.

What I've got happening is little pits in the hull that I'm sure is caused by electrolysis. I've disconnected all the ground wires from the battery and then reconnected them one by one checking for a ground between the hull and positive post. I found that the main ground wire going to the Merc is grounding to the hull. Is it possible to isolate the motor ground from the hull? What kind of options do I have?

Also, how can I add more zinc? I've only got one piece affixed to the lower unit. I saw in another thread about welding directly to the hull. Is that the most recommended? Is there a formula, or rule of thumb, for the amount of zinc one should have?

Thanks.

[Get Bent]

make sure all of your wires to your lites fish finder ect are not grounded to the hull check with a mechanic a good one on the engine i think you can ground it to the battery you can put two 2 pounders bolt or weld on on the out side of your boat also bolt one on the inside on a stringer by the drain plug when you get salt water inside your boat you want it there also call Sean at North River he can give you info on your engine hope this helps i had the same problem on my a.w. graemlins/idea.gif