galvanic isolator on 350 mariner

[bud37]

Does anyone with a mariner know where to find this isolator.......info that came with the boat says there is one and I would like to check it for function. This boat like many had the original zincs on it, that will be changed to magnesium this coming spring.So what say ye.....

[Viper]

I don't have a Mariner but try looking behind the electrical panel. Maybe a Mariner owner will chime in with an exact location.

Before you make the switch to magnesium anodes, consider aluminum instead. The new alloys used in aluminum anodes are great for fresh water inboard applications now. They last longer, are better for the environment, and are much cheaper than magnesium. You also can't overprotect with aluminum like you can with magnesium in a fiberglass application. You may have a challenge finding all the anodes you need in aluminum as the trend is slowly catching on but they are out there.The only time I consider using magnesium anodes on fresh water inboard applications now is if the vessel has aluminum hardware in the water such as hydraulic swim platforms.

[bud37]

Viper , my idea is that if I find this isolator and it is working as designed then I will use Mg anodes , but if I can't find this thing then I will use Al so as not to overprotect and you are right much cheaper.... I used the Mg anodes on the previous boat with good results, but on this one there was a few spots on the props that appear to be corrosion , which could have come from the batteries being partially submerged due to plugged drains , a guess maybe but there was voltage leaking across the battery tops and oxidized zincs on the shafts.

I am hoping someone knows where that isolator is.........

[Viper]

Isolator or not, make sure you have good connections throughout the bonding system and that there are no DC or AC connections lying in the bilge unless they are waterproof.

You're better off changing to aluminum anodes anyway, add more of them if you feel you need more protection. Do you have shaft and trim tab anodes? Do you have rudder anodes, and a Diver's Dream on the transom? Are the shaft anodes really close to the struts? They should be.

Can you describe the corrosion on the props or better yet, do you have pics?

[bud37]

So here is the story.....two or three small rust like pimples on each prop at survey, no where else,same at haul out, they picked off and we cleaned the props, looked ok after......now there were zinc anodes on the shafts maybe a couple inches from struts, zinc plate on transom and the only zincs that appeared to be doing anything were on the tabs ( no rudder zincs).
Now the aft bilge pump between the engines was not working at survey and was replaced but there was evidence of 4 to 6" of water in that section around the batteries and there is a small well around the shaft logs that was also full of water thus completing the circuit I believe so far.If you whacked the pump it came on.!
I have checked all the bonding that I could touch and all seems to check out fine with meter, no wires in bilge and now the bilge is bone dry ( cleaned the plugged deck drains etc)
I am going to replace all the above anodes this spring with either Al or Mg ,jury is still out.Probably Al as the martyr site seems to recommend them but you have to get the right Al anodes, there is an alloy involved.So thats it Viper .......still got to find the isolator though, we have about 600 boats and by the looks of things in the yard lots of boats with just old zincs...wow long post...

[Viper]

If the current anodes are zinc and a few years old, they haven't been doing a single thing for you.

Qr Bbpost....we have about 600 boats and by the looks of things in the yard lots of boats with just old zincs...

That's really a marina thing. They should be educating their customers. While some won't be swayed no matter how logical the explanation, most are receptive to common sense. It really is best for all the boaters in the marina if everyone replaces their zinc anodes. It's in your best interest to spread the word, especially to the boaters beside you.

[bud37]

Come on 350 owners bud needs to find it, its winter now so can't look further.....lol...

[bud37]

Found em, there are two, one for each shore circuit.....everything checked out fine , working as they should.......

[Viper]

Great, how about letting the rest of us in on the location!

[bud37]

Sheesh....woops ,missed this...was hoping to get pics as I was going back in there, but.... .....they are mounted in with all the shore power/ 110 stuff......30 amp zinc saver II,one for each line, don't think they are the ones with the caps in there, judging by how they tested. These appear oem......