Sacrificial Anodes and Galvanic Isolators

[Jonah]

Hi all,

I've read on this forum a little bit about sacrificial anodes, and have begun to wonder whether my trim tabs have them. My boat is in the water, so I'll need to dive in order to check.

But then I learned that my boat has a galvanic isolator, which I understand prevents corrosion of submerged metal parts (like trim tabs).

So, are anodes needed when one has a galvanic isolator? Or do they work together in some way? Yes, I'm Googling this now, but of course I suspect that some of you will know this very well.

Thanks as always.

 

[Ozz043]

My Marlin has anodes on the trim tabs....
I’m not familiar with galvanic isolators but I know I have one linked to the shore power ..... it doesn’t stop anything submerged from galvanic reaction

 

[DennisG01]

You have shore power on a 208?

Anodes are always needed on any underwater gear. The anodes and GI are for two different functions (although related). GI's are used when you are hooked up to shore power.

 

[Jonah]

Thanks both.

Dennis, maybe I need to update my profile, but I'm now in a 1995 272, having sold the 208 about 15 months ago.

I'll check to see if I have anodes, and will do some reading on what they do vs what a galvanic isolator does.

 

[Fishtales]

My dealer didn't put anodes on my tabs. Been 12+ years and they look fine. I guess if they rot away and I replace I'll add. I paint them with bottom paint every 3 years. No corrosion yet...

 

[DennisG01]

Obviously, it can't hurt to have the anodes... but because tabs, themselves, are physically isolated from boat's grounding system, this is one area that can sometimes be skipped when putting on anodes. But, often, it depends on the specific water you're in, your set up (OB's, stern drives, inboards, etc), other boats around you and the marina's electrical system.

 

[Fishtales]

Yup, just saying I have not seen them on the GWs up here.