What is a 'Strum Box'?

[sailorman]

is not seawater a conductor

Surely if not that would negate (ho, ho) the point? The idea is to ensure that current flows the "right" way, which is to disolve tha anode rather than any other metal in contact with the water. Unless they are bonded together the current cannot flow at all.

Mike.

 

[VicS]

The rudder is wood, I pulled the SS bolts out the other day and they have only JUST started to deteriorate in the middle of the bolt e.g. halfway up the stem! Nor sure if the hull anode is connected to anything, will check. The last boat had wires going to the seacocks, prop, et etc but this doesn't have anything. Good, less complication for me Doh!

The rudder doesn't need an anode then.

Presumably the mountings are stainless if the bolts are
Seal the joints between the wood and the mountings and seal the bolts in to prevent water creeping in and causing crevice corrosion. Something to keep an eye on in the longer term.


You do need to check on what your anode is supposed to be doing..
Seacocks etc should be corrosion resistant. Plastic, bronze or DZR brass. They should not be connected to the anode(s)

 

[prv]

As the owner of nearly a sister boat...

No need to wire up anything to the rudder hinges. The bolts are worth keeping an eye on - my old ones were corroded almost through, and the replacements started to follow them. Might be worth drawing one of the bottom ones (they seemed to go first) every other year or so to check. Otherwise seal them up well with black sikaflex, as Vic says. In extremis, Classic Marine would be able to make you a crevice-corrosion-free bronze set of hinges and bolts, as they did for us, but only necessary due to the exceptionally corrosive mud in our berth next to a scrapyard.

The hull anode should be wired to the engine block inside the hull. The shaft linkage (assuming the same as ours) is all metal so will carry the current to the prop.

Pete

 

[Zagato]

Thanks... I should be OK with the current set up then. I put the bolts back with marine sealant so they should be OK (Silkaflex may have been better but I was worried about not getting them back out again if I had used that, a tap one end may do the job though, I may take them out again and use Silkaflex). I know of a Crabber 24 that lives in Ci Marina and he has had to put on anode on each bolt as they deteriorate quickly after just 6 months - think this can be a problem with marinas!

Thanks Pete, I'll look into that. I'll probably swap them out every couple of years if they need it so some right size back ups would be good...

 

[charles_reed]

So, there you are - just like the civil service, all instructions in triplicate!

Seems to me to be in quintiplucate.