Anodes for the Broads?

[larson250]

Hi,

Apologies if this has been done to death, but i'm moving the boat to the Broads in July (Beccles area) and wondered which anodes best suit the water.

Aluminium, Zinc or Magnesium?

I intend to go out to sea occasionally also.

Any advice greatly received.

Dean

 

[dombuckley]

Assuming your boat is GRP, if you were staying permanently in fresh water, then magnesium would be the way to go. However, magnesium will not cope with forays on the briney (no matter how short).

If you stick with zinc, be wary, because zinc will fur over with oxidation in fresh water: this completely isolates it, so that it will not protect against galvanic action once the vessel returns to salt water. Be prepared to thoroughly scrub the anodes prior to any trips back to sea. OK for occasional trips, but you don't want to be doing this all the time.

Aluminium does not suffer from this problem, but will not last as long in salt water. As long as the trips to sea are only short, this may be the best way to go.

Which ever one you choose, bear in mind that your vessel is far more prone to galvanic action in salt water than fresh, so keep her prepared for saltwater use. Many hireboats in the Broads have been running around for 20-30 years with no anodes whatsoever, with no significant galvanic problems in the freshwater environment.

Of course, if your boat is wood, then stick with zinc.

Dom

 

[Greg2]

Don't know what your boat is but we switched from zinc to aluminium last year (Fairline Targa with twin outdrives) on the basis that they are okay for both fresh and salt water and the manufacturers claim that they last longer. They did!! Not a lot of wear at all and for the first time ever I didn't change them for the new season (no corrosion of the legs etc either).

We were berthed in salt and made occasional forays into the broads as opposed your plans to keep in fresh. Should be okay though - a mate has just moved back into the broads and has left his aluminium anodes on.

 

[larson250]

Cheers Dom,

I was thinking Aluminium as a bit of an all rounder, and yes the boat is GRP.

Dean