Hamble anodes

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Aldous

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I am investigating the possibly quicker decay rates of anodes on the river Hamble. If your boat is moored on the Hamble have you noticed this quicker decay rates of anodes? If so how often do you have to replace them?

Thanks
 
The actions will depend on the results. But better advice and education about anodes if possible and working with the bodies involved to hopefully come up with some solutions. This issue is one which has been expressed by a number of boat owners on the Hamble, it is likely to occur elsewhere also.
 
We are in Swanwick and anode decay is relatively slow - main hull anode probably 50% wasted in a year although I replace it annually, trim tabs 60% ditto and thruster anode 40% which I replace every 2 years. That said the engine anodes on my alloy based Yanmar waste quite quickly and last only about 9 months.
 
Mid river mooring for 11 years, only needed to change hull anodes at about three to four years. Prop anodes were at least every year, prob more like 9 months.
 
We were in Port Hamble for 1 year between lift outs.

At annual lift out, we had to have two new sail drives. Ours looked like they had suffered a really bad attack of measles. The anodes on the sail drives were long gone.

I had extra anodes fitted to the hull of the boat and wired in after that.

I'm still not sure if it was caused by some fault with our boat, a neighbour, the river, or the marina. But, I for one would not leave a boat in Port Hamble checking the anodes only once a year.

Garold

No trouble again though once we had replaced the drives, installed extra anodes, and moved from Hamble.
 
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2 anodes on each shaft totally gone in a year, 2 on each tab plus main anodes on hull 50% gone in year at Hamble Point. At least we know they are working, I would be more worried if they were not disappearing.
On previous boat we had to have 2 new props when shaft anodes were left off, Neil
 
Your link does not work on my Mac, however I moor midstream at Foulkes (between the rail and motorway bridges).

I was suffering heavy anode wear for the first two seasons with OB, but this was due to issues with the boat itself now resolved, rather than the river. I also use a dangling anode at the mooring, and I am now getting at least two seasons from a 4kg anode above each shaft. I did think it might have been the brackish water especially after heavy rainfall, and definitely think this contributes to the barnacles, but not the anode wear.

I recall Volvopaul suggesting horrendous anode wear at the Cabin yard, just a couple of hundred yards away, so possibility variations due to localised stray current issues. AC faults are worse than DC ones for anode erosion due to stray current.

Now if you can come up with an anode that also prevents barnacles - well ...
 
Aldous said:
Thanks everyone these responses are really helpful.

I have a survey about this issue to determine trends and hotspots within the Hamble and wider Solent if anyone is interested in completing. From this we hope to test some of the reasons suggested and hopefully come up with some solutions. See survey link below:

https://docs.google.com/forms/d/1WOf...G_IK8pCao/edit
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Doubt you will find anything that looks like a pattern. Think about why you have anodes and you will realise that location is only one of many variables that have an effect on the rate of erosion. Dont think either that the Hamble in general will be much different from any other river with marinas and a high concentration of boats.
 
superheat6k said:
Your link does not work on my Mac, however I moor midstream at Foulkes (between the rail and motorway bridges).

I was suffering heavy anode wear for the first two seasons with OB, but this was due to issues with the boat itself now resolved, rather than the river. I also use a dangling anode at the mooring, and I am now getting at least two seasons from a 4kg anode above each shaft. I did think it might have been the brackish water especially after heavy rainfall, and definitely think this contributes to the barnacles, but not the anode wear.

I recall Volvopaul suggesting horrendous anode wear at the Cabin yard, just a couple of hundred yards away, so possibility variations due to localised stray current issues. AC faults are worse than DC ones for anode erosion due to stray current.

Now if you can come up with an anode that also prevents barnacles - well ...
Click to expand...

Yes your right Trevor it was bad at cabin but worse further up river with the same boat and very slow in Swanwick where I was nearly at the end so more mid river. I wonder how I'll get along now with you at Foulkes.
 
B
superheat6k said:
Your link does not work on my Mac, however I moor midstream at Foulkes (between the rail and motorway bridges).

I was suffering heavy anode wear for the first two seasons with OB, but this was due to issues with the boat itself now resolved, rather than the river. I also use a dangling anode at the mooring, and I am now getting at least two seasons from a 4kg anode above each shaft. I did think it might have been the brackish water especially after heavy rainfall, and definitely think this contributes to the barnacles, but not the anode wear.

I recall Volvopaul suggesting horrendous anode wear at the Cabin yard, just a couple of hundred yards away, so possibility variations due to localised stray current issues. AC faults are worse than DC ones for anode erosion due to stray current.

Now if you can come up with an anode that also prevents barnacles - well ...
Click to expand...
My Azi was moored at The Cabin, between the A27 bridge and the railway bridge, and suffered very rapid anode wear. She is now at Portishead, and ok so far, but I have added a Galvanic Isolator. I think the current surge where the river narrows at the A27 has an impact, and VolvoPaul had a suspicion about the metal railway bridge.
 
rafiki_ said:
My Azi was moored at The Cabin, between the A27 bridge and the railway bridge, and suffered very rapid anode wear. She is now at Portishead, and ok so far, but I have added a Galvanic Isolator. I think the current surge where the river narrows at the A27 has an impact, and VolvoPaul had a suspicion about the metal railway bridge.
Click to expand...

I saw what you did there :D
 
At Eastlands at the top of the Hamble we could only get 6 months out of our Volvo 290 DP prop anodes. The bar anode would last a year
 
Aldous said:
I am investigating the possibly quicker decay rates of anodes on the river Hamble. If your boat is moored on the Hamble have you noticed this quicker decay rates of anodes? If so how often do you have to replace them?

Thanks
Click to expand...

Aldous you might consider amending your survey to include a question about galvanic isolators (not that I'm an expert!) as these have the potential to slow anode wear afaik....
 
A couple of years ago I acquired a new boat and noticed a significant faster anode wear than the previous boat, one difference that new boat did not have a galvanic isolator. I weighed the anodes, fitted a galvanic isolator and weighed the next set of anodes after exactly the same immersion time , same boat, same time of year and same berth. After the GI was fitted I had a 25-50% slower anode wear, transom shield anodes wearing the fastest and trim tabs the slowest. Anodes are on a 40' twin engined boat with outdrives. The boat is moored at Swanwick D pontoon.
 
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