Anode

[hurley]

Hi Can anyone help me.

There ia a large anode to starboard of the inboard rudder just below the waterline on my hurley 22. (outboard engine version) On the inside of the annode there is an earth wire which runs to the negative junction bar for the boats electrics.

The boat was re wired by the previous owner, and I just felt the need to check this out as one or two bits that he did I have had to re do in respect of the wiring. Just felt I would ask the experts.

so..Is this normal practice?

Thanks in anticipation of your advice Nick
Has anyone

 

[Cloven]

Basically yes. It is best also if the anode is connected direct to the engine as this will be the main negative on the boat.

 

[santeana]

You seem to have a negative bus bonded to the anode which is how it should be - or to be exact how I've done it!

 

[santeana]

Dave, it's an outboard.

 

[hurley]

thanks for taking the time to help me out on this.

Cheers guys Nick

 

[andy_wilson]

There doesn't seem to be any normal practice for anodes, but the best advice I would offer (pass on) for small GRP hulled boats is:

Wherever possible attach (mechanically and electrically) the anode to what it is protecting (eg direct to outboard motor leg, shaft anode for propellors and shafts, slug bolted to steel keels and rudders, pencil anode screwed into engines and heat exchangers).

If you can't attach it, locate it close by, and connect internally (eg pear anode adjacent to p-braket, electrically connected internally with lowresistance connections between the internal bolts or studs).

Good quality bronze skin fitting seldom need either protection or bonding. Certainly not heads fittings up at the front for instance, but engine water inlets close to stern gear may require specialist advice.

Never connect the bonding to the electrical system. The electrical system shouldn't be in the water so there is no need. However a fault in the main wiring may provoke stray currents and rapid deterioration of anodes and then that which they were protecting.

IF you have an outboard that charges the batteries, and is bonded via common earths, check the price of a new leg and gearbox before you decide to connect it up to other electrical systems AND anodes.

SO, I am just wondering what it is protecting. Is it a steel rudder, is it to protect the rudder stock, is it to augment the protection for the engine.

Certainly I can figure no good reason to attach it to the electrical earth system for all the reasons above. If it is for the outboard leg, run a wire from the anode, under the hood with the rest of the outboard wiring, cimp on agood teminal and attach with a serrated washer to a suitable stud on the top of the leg or powerhead.