P-bracket corrosion

[no3l]

Hi

I have. noticed traces of corrosion on the P-bracket of Rhiannon (SO36i, 2008) when commissioning this year.

From new there hasn’t been an earth strap on the bracket, is this standard for Jeanneau?

The bracket is fully encased on the inside of the hull so I can’t fit a stra, would a galvanic isolator help?

I would appreciate any suggestions.

Thanks
Noel

[Charlie-Bravo]

Odd that it has only been noticed recently .... 

You have probably already read the posts here about the braided cable that a lot of Jenneau boats have, that corrode away, and are usually covered in gel coat and glass fibre at the bracket bolting, perhaps yours just got buried....... and is hiding in the gel coat.

It would seem a worth while and necessary task to dig out one P bracket bolt and add a cable to stop the corrosion.

Some folk here have added an anode to the P bracket, but not being connected up to the ground circuit , I wonder if it has worked , it might slowdown the corrosion bit.

Yout could bolt a strip of brass / copper  from the bracket to the hull anode, but it's not a tidy solution, adding the internal cable is going to be much neater and last a lot longer.

Multitool and hoover recommend 

CB

[no3l]

Thanks CB,

Yes it only showed up this year, we take the boat out every winter and this is the first time it has occurred. Nothing has changed on the boat so I'm not sure if it is anything to do with the connections in the marina.

We don't use shore power.

The only thing that may have any significance is our new neighbour in the marina is a steel hulled motor boat. But my understanding of galvanic corrosion is that it needs an earth connection but as we are not using shore power this connection is not (should not be) the issue and I cannot see a galvanic isolator being of any use in these circumstances but an anode on the P-bracket may help.

Questions for other SO36i owners:
Is there an earth cable on the P-bracket that I am missing?
Has any one retro fitted one?

Thanks
Noel

[no3l]

Hi,

Sorry to be a pain on this topic.

On page F11/1 of the schematic diagram an earth connection is shown for the P-bracket.

Does anyone know if this is buried in the glassfibre and connected to earth elsewhere in the boat because I cannot find any cable in the area of the bracket.

Thanks again
Noel

[Charlie-Bravo]

If you are still out of the water, a simple resistance test with a multimeter from your P bracket to either the hull anode or prop shaft will determine if such a hidden cable exists, doesn't have to be an expensive instrument,  it just needs to show a connection or not.

CB

[Trevor]

Hello No31,

If you search in this topic it has had a fair bit of coverage in the forum. One of the posts is this one that may at least let you know you are not alone!
jeanneau.proboards.com/thread/7594/earth-bonding-bracket?page=1

Anyway, good luck with it.

Regards

Trevor

[no3l]

Hi Trevor,

Thanks very much for that link, I missed that thread. It's very useful.

I'll be checking the boat over the week and and will update on how I get on.

Thanks again
Noel

[no3l]

Hi,

The story continues.

I checked the continuity between the P-bracket and earth and there is no connection.

I emptied the aft cabins and still couldn't see any sign of an earth strap for the P-bracket and there is no sign of a corroded cable. In fact the housing for the bracket is clear so it looks as the earth strap was never fitted.

I had to launch so I've put an anode on the bracket as per previous threads so hopefully that will help protect the bracket while I figure out how to fit an earth strap.

Regards
Noel

[Trevor]

Hello Noel,

That is very interesting that you can see no sign of an earth strap. I think the anode you have fitted will provide the required protection.

Trevor.

[Trevor]

Hello Noel,

That is very interesting that you can see no sign of an earth strap. I think the anode you have fitted will provide the required protection.

Trevor.