What type Anode for Dutch Meers

[apollo]

Hi

Considering moving boat to Holland next year, currently the boat is on Fresh water and therefore has Manganese Anodes, I know its Zinc for Saltwater.

So what type of Anode would be best for the Meers in Holland eg VeerseMeer? /forums/images/graemlins/confused.gif

Mike

 

[nedmin]

Aluminium,most Dutch boats are ally.

 

[VicS]

This is the advice on anode material selection on the MGDuff website
[ QUOTE ]
As a general rule owners should fit the anodes suitable for the environment they most regularly berth in and the following table provides a useful guide:

Salt Water Fit Zinc or Aluminium Anodes
In Brackish Water Fit Aluminium Anodes
In Fresh Water Fit Magnesium Anodes

Some vessels will from time to time move between salt and fresh water, others are berthed within marinas and behind tidal barriers where the water is enclosed and likely to be brackish or even virtually fresh. Owners must be aware of the effects that this may have on their boats and fit the correct cathodic protection system to avoid corrosion.

Not all anodes are suitable for every environment, for example the surface of a zinc or aluminium anode will if left in fresh water for some time become covered with an off white crust of oxide which effectively seals the anode and stops it working even when returned to salt water. Zinc Anodes suffer a similar problem even in brackish conditions whereas Aluminium will continue to operate effectively in river estuaries and other areas of brackish water indefinitely. The consequences of this passivation of the anode are that the next most anodic item within the anode bonding system will start to sacrifice itself which could of course be very serious.

It is therefore very important to check Zinc and Aluminium anodes after any trips into fresh water and if necessary clean off or change the anodes.

Should a vessel move into fresh water for more than two weeks MGDUFF recommend that an alternative anode system is used suitable for fresh water situations. Magnesium Anodes on the other hand have a much higher driving voltage than zinc or aluminium making them highly suitable for use in Fresh Water, they will however become very active in salt water where they will probably only last a matter of months. Protected surfaces can build up a layer of off white calcareous deposit which will be difficult to remove.

Magnesium anodes are not designed for prolonged use in sea water and if you are taking your boat into a salt water location for more than seven days (Fourteen days in any one year) you should consider changing the anodes. Magnesium Anodes should never be fitted to wooden hulled vessels as they can damage the timber.


[/ QUOTE ]

 

[thalassa]

Veerse Meer used to be brackish water, but is now brought to the same level as most of the Schelde Delta, i.e. salt water.
Same for the Grevelingenmeer, which also can be considered saltwater. The level of salt is regulated by the flood barriers.

This does not apply to the "meren" or "plassen" in the North of Holland, which are mostly freshwater.

 

[kingfisher]

Veerse Meer is brackish, Oosterschelde, Westerschelde, Grevelingen, Haringvliet are sea water

 

[heerenleed]

Aluminium is the choice if you sail in both fresh and salt water. And. of course, in brackish water...
cheers

 

[Emjaytoo]

The status of the Veerse Meer is of particular concern for us as we keep our boat there permanently. It is new and was supplied on the east coast with presumably zinc anodes (I'm waiting for the dealer to confirm that). Do I need to change the anodes? If so can it wait til the winter lift out?

Next weekend, when I'm up at the boat I will taste the water to see if it is salt. In the meantime does anyone know for a fact what the water is?

 

[RCGrootveld]

[ QUOTE ]
Veerse Meer is brackish, Oosterschelde, Westerschelde, Grevelingen, Haringvliet are sea water

[/ QUOTE ]
Grevelingen: Brackish
Haringvliet : Fresh
Is what we learn the kids at school .....

 

[thalassa]

I can't point you to any English-language website with the info, but all online Dutch official publications (Rijkswaterstaat etc.) point to the same: Veerse meer is presently SALT WATER, approximately the same as the Oosterschelde and Westerschelde. It used to be brackish, but more seawater has been allowed in since more than a year ago, due to environmental problems.
And yes, I've tasted it last year, salty it is !