BETA engine anodes - ouch!

[sbrockman]

I replace the anode on my Beta 1005 (28hp) every year as it's pretty much gone. I ordered 3 this year from Beta and got stung for £42 inc. postage, thats nearly £15 each. Are there any alternative, and cheaper, suppliers out there?

 

[earlybird]

I paid £17 for one Beta anode last year, like you, I wondered if there was a cheaper route, including casting one. However, it occurred to me that it just might be magnesium, since it is protecting an aluminium, ( I think ), heat exchanger body. The manual refers to a "zinc" but I am unsure. Does anyone know for certain

 

[Talbot]

I use zinc to protect aluminium in sea water - doesnt magnesium do the same in fresh water?

 

[earlybird]

[quote doesnt magnesium do the same in fresh water?

[/ QUOTE ]
That's why I'm asking, the Beta anode is immersed in the fresh-water/ antifreeze coolant.

 

[lydiamight]

Have a look on www.zincsmart.com Looks to be either £2.25 or £2.12 depending on the model. No connection etc, etc--just a very satisfied customer.

 

[jeanne]

Lydiamight

I´m sure you were being helpful, but you are making me feel inadequate ! How do I get from the site home page to the 2.25 a throw bit?

 

[sailorman]

Re: Lydiamight

http://www.zincsmart.com/

 

[VicS]

[ QUOTE ]
doesnt magnesium do the same in fresh water?
-------------------------------------------------------------------
That's why I'm asking, the Beta anode is immersed in the fresh-water/ antifreeze coolant

[/ QUOTE ]

Magnesium is used for anodes in fresh water because zinc becomes coated with an oxide crust which renders it ineffective but it is not used in salt water because it is too active and would be rapidly consumed.


But if the engine cooling system is filled with an inhibited antifreeze solution why do you need a anode at all? Can anybody tell me of any car engines that have anodes? Is it just that there is always a risk of a heat exchanger leak contaminating the freshwater circuit with sea water?

 

[earlybird]

[ QUOTE ]
But if the engine cooling system is filled with an inhibited antifreeze solution why do you need an anode at all?

[/ QUOTE ]

Good question Vic, but the fact remains that Beta fit one in the heat exchanger, and something gobbles them up at a considerable rate. Of course, the cynical view is that it's good business! Am I correct in thinking that zinc would promote, rather than inhibit, corrosion of aluminium? I have the remnants of an old anode. What I need is a DIY test for identifying the metal, trying to set fire to it perhaps?

 

[theforeman]

i don`t know the answer but could it have something to do with the fact that the heat exchanger on the marine engine has fresh water on one side and salt water on the other ?

 

[PuffTheMagicDragon]

My heat exchanger is aluminium alloy (Lombardini) but the tube nest is not; nor are the water passages in the block. Could that be why there is a zinc anode?

 

[doug748]

Thanks for that Ray, an excellent saving; esp as the Beta needs an anode every six months.

 

[VicS]

Earlybird, Foreman and Puff
A zinc anode would be appropriate in the seawater side of the heat exchanger. It would protect aluminium, just.
In fresh water zinc is no good hence the use of magnesium but the question i was asking was why was a anode deemed necessary in a fresh water cooled engine filled with an inhibited coolant solution. Car engines are not fitted with anodes, as far as I know. I wondered if it was considered that the possibility of a heat exchanger leak allowing salt water in to the primary circuit was the reason. If it was a zinc anode would still be inappropriate as it would have become coated in oxide while in fresh water and therefore rendered ineffective. A magnesium anode would therefore be required but that would be consumed rapidly in the event of salt water entering the system.