P-Bracket "earth" strap

[pagoda54]

Our 42i has a thick copper braid strap coming from the P-bracket - to the engine mountings.  It is not in great condition- stiff and discoloured. How critical is this strap?  The P bracket is bronze - with no direct contact to the shaft anyway. If it were isolated from the engine I can't see any great downside??
Any experience or comment on this strap from other boats? Replacing it would not be easy!

By the way, Flex-o-fold prop -no sign of any galvanic corrosion. Ditto shaft. Shaft anode lasted a season (as expected).  The prop anode was part used up.  The boat has a galvanic isolator

thanks, Graeme

[pbunning]

There is no strap on my 33i. I wish there was. It is used, I guess, for cathodic protection - connecting the bracket to the engine block and so to the anode via the gearbox and shaft. On my boat. I have noticed a slight amount of de-zincification, which I have been monitoring over the last few years - not much, but there.

[pagoda54]

Apr 22, 2018 19:52:32 GMT pbunning said:

There is no strap on my 33i. I wish there was. It is used, I guess, for cathodic protection - connecting the bracket to the engine block and so to the anode via the gearbox and shaft. On my boat. I have noticed a slight amount of de-zincification, which I have been monitoring over the last few years - not much, but there.

I decided on a typical "belt and braces" solution to the issue.  I've added a pair of small clamshell style anodes to the P-bracket. Described as "trim-tab" anodes, about 50mm diameter- about 20mm thick each at their thickest. There is not that much P-bracket to be honest. There are thicker versions anyway- monitor until next winter.
 
Required one 5mm hole and some loctite for fixing. I don't think I've compromised the P-bracket by one 5mm hole and I have some additional protection beyond the slightly dubious engine-P bracket strap.

[vasko]

The connection is quite important just measure if the is connection between the p-bracket and the anides ... if not repair it

[Erik]

Apr 23, 2018 20:06:41 GMT pagoda54 said:

Apr 22, 2018 19:52:32 GMT pbunning said:

There is no strap on my 33i. I wish there was. It is used, I guess, for cathodic protection - connecting the bracket to the engine block and so to the anode via the gearbox and shaft. On my boat. I have noticed a slight amount of de-zincification, which I have been monitoring over the last few years - not much, but there.

I decided on a typical "belt and braces" solution to the issue.  I've added a pair of small clamshell style anodes to the P-bracket. Described as "trim-tab" anodes, about 50mm diameter- about 20mm thick each at their thickest. There is not that much P-bracket to be honest. There are thicker versions anyway- monitor until next winter.
 
Required one 5mm hole and some loctite for fixing. I don't think I've compromised the P-bracket by one 5mm hole and I have some additional protection beyond the slightly dubious engine-P bracket strap.

Pagoda54 -

I have the same issue with the copper braid on my Jeanneau 39i that many others have had, so I am planning to install a trim-tab type clamshell anode.  May I ask if you through bolted the clamshell by drilling a hole straight through the P-bracket, or did you drill a pilot hole to screw the clamshell directly into the P-bracket?  I'm assuming you did the former.  How difficult was it to drill through the P-bracket?  (I don't think I've ever drilled into bronze before.

Thanks,

Erik

[andreshs1]

Hi all

very interested to see an actual photo of the final installation

cheers
Andres