Up she rises (with pics)

[crazy4557]

My boat at Itchen Marina yesterday being lifted for a 'lift and hold' survey for the potential new buyer.

Unfortunately, the surveyor discovered evidence of an electrolytic corrosion problem that has caused quite bad corrosion of both props turning them pink!! The anodes are all doing their job and the only clue maybe that the pencil anode on the port engine was 98% eaten away whereas the starboard one was far less dissolved!! Maybe a pointer but then I can just about wire a 3 pin plug so what would I know!
When she was lifted in the summer for a mid season scrub I had a good nose around the props and sterngear and they looked completely fine, all I've changed since is to have a generator fitted by a professional. Potentially this maybe the cause but I really need to get an electrician who is experienced in this type of probelm to take a good nose around.

Does anyone know of a suitable one in the Solent area?

I don't have pics of the props as the battery ran out before I could take them.

 

[Ripster]

I used Bob Russell of www.barelectrical.com to refit, integrate and install my new Garmin plotters and make them talk to the existing Raym gear and AP. He did a first class job and always cleaned up after each day. No connection (LOL the pun!) he just did a very good job for me! Certainly seems to know his way around boat electrics and electronics. He does a fair bit of work in my Marina and is well known here.

 

[Bandit]

Firstly get the shaft bonding checked, brushes or connection accross the plastic R&D coupling if it has one, does the boat normally have shaft anodes?

MG Duff make shaft brushes.

If the props are well pink and or scaly you probably need to think about a replacment pair can you still read the prop sizes which are stamped on them, try Clements Marine. If they are pink or scaly they have lost a lot of their strength but probably ok for a spare pair.

You need a good marine electrician who has all of the correct gear for testing the boat in the water to work through your bonding system, and to eventualy check the boat in the water on its berth, sometimes its the boat next door or an earth fault on the pontoon or a pile. Also get the galvanic isolator checked if it has one or get one fitted.

If it was me I would also fit shaft anodes on each shaft with jubilee clips above and below to stop slipping with the tails trailing when going ahead. I have brushes and shafts.

 

[Wiggo]

Ah, Andy, that'll mean you've just found my new sacrificial anode system, then! I'd better get my butt down and check mine out asap...

(for those unaware, he's moored next to me...)

 

[volvopaul]

Hi Andy, it will be the shaft brushes as the other side is ok there are no bonding wires on the shaft plastic coupling as they rely on the brushes, I have fitted bonding wires on many Fairlines as a back up.

 

[Bojangles]

This might sound like a daft question but here goes, should every boat with shafts have shaft anodes fitted. My boat (an F43) was just lifted and I was advised to fit shaft anodes as none were present, so I've had them fitted.

 

[jfm]

This might sound like a daft question but here goes, should every boat with shafts have shaft anodes fitted. My boat (an F43) was just lifted and I was advised to fit shaft anodes as none were present, so I've had them fitted.

IMHO shaft anodes are a bad idea and I would never have them and never have had them. It is perfectly possibly to connect (electrically) the shafts to the main anodes, using brushes, or using bonding straps as described in volvopaul's post. If you do that, the shaft anodes are pointless. Adding an eroding element to a shaft is asking for trouble becuase as it fizzes away it can come loose. It might not, but it can. It also adds drag and turbulence in front of the props

There are loads of well kept boats that never have shaft anodes and are perfectly fine corrosionwise.

 

[Bojangles]

IMHO shaft anodes are a bad idea and I would never have them and never have had them. It is perfectly possibly to connect (electrically) the shafts to the main anodes, using brushes, or using bonding straps as described in volvopaul's post. If you do that, the shaft anodes are pointless. Adding an eroding element to a shaft is asking for trouble becuase as it fizzes away it can come loose. It might not, but it can. It also adds drag and turbulence in front of the props

There are loads of well kept boats that never have shaft anodes and are perfectly fine corrosionwise.

Thanks for that, yes there are brushes crossing the R & D couplings, I'll take them off (if there still there) the next time the boat is lifted. I wish I had posted this query on here before I fitted them now.

 

[crazy4557]

Hi Andy, it will be the shaft brushes as the other side is ok there are no bonding wires on the shaft plastic coupling as they rely on the brushes, I have fitted bonding wires on many Fairlines as a back up.

I subsequently found that both shaft brushes to be broken or seized which I thought was cause of the problem but the surveyor said not.
Maybe someone can explain what they do if they don't stop the corrosion that I now have?
Sorry to be a muppet but electricity and me don't get on...........

 

[Bandit]

I had problems with cathodic protection on a boat 10 years ago since then i have had shaft brushes and shaft anodes for belt and braces.

Shaft brushes especialy the plastic ones are delicate, my boat has a solid stainless bar to mount them and few builders bother to do the job properly.

Straps accross R+D couplings are also prone to failure.

As I said I put a stainless jubilee clip above and below with the tails trailing when running ahead and i have never had one slip.

The problem with cathodic protection is you generally dont know whether its working untill you lift the boat the next time and sometimes its too late.

Also : You need a good marine electrician who has all of the correct gear for testing the boat in the water to work through your bonding system, and to eventualy check the boat in the water on its berth, sometimes its the boat next door or an earth fault on the pontoon or a pile. Also get the galvanic isolator checked if it has one or get one fitted.

 

[crazy4557]

I had problems with cathodic protection on a boat 10 years ago since then i have had shaft brushes and shaft anodes for belt and braces.

Shaft brushes especialy the plastic ones are delicate, my boat has a solid stainless bar to mount them and few builders bother to do the job properly.

Straps accross R+D couplings are also prone to failure.

As I said I put a stainless jubilee clip above and below with the tails trailing when running ahead and i have never had one slip.

The problem with cathodic protection is you generally dont know whether its working untill you lift the boat the next time and sometimes its too late.

Also : You need a good marine electrician who has all of the correct gear for testing the boat in the water to work through your bonding system, and to eventualy check the boat in the water on its berth, sometimes its the boat next door or an earth fault on the pontoon or a pile. Also get the galvanic isolator checked if it has one or get one fitted.

I've got MG Duff down next week to take a look, hopefully he will say 'bingo fault found' quickly or it's going to cost me big bucks for him to trace!