Is this anode too big?

[Rhylsailer99]

I bought a 5kg anode a few years back and thought it was tol big so I fitted a 2kg one. The old 2kg anode now needs replacing and I am thinking is 5kg too heavy for a 28ft boat. I atill have the 5kg anode available and not sure if I should buy another 2kg and sell the 5kg one or just fit the 5kg anode.

 

[Rhylsailer99]

The centres are the correct size at 200m.

 

[Mister E]

Will you or the boat notice the extra size and weight?

 

[Rhylsailer99]

Will you or the boat notice the extra size and weight?

I think I will just fit it then. I guess after a short time it will loose some of its weight.

 

[Seastoke]

It will last 2 years. Make sure the bolts are good and check cables on the inside bilge.

 

[Tranona]

Yes. Twice as big as you need. This is what is normally fitted marinesuperstore.com/anodes/zinc-hull-anodes/z-guard-zinc-pear-shaped-hull-anode-2-1kg-zg77kit?utm_source=google_shopping&utm_medium=pcn&utm_campaign=MSS&utm_term=ZG77KIT&gad_source=1&gclid=CjwKCAjw-JG5BhBZEiwAt7JR65rySGNCHLTL25AUMBSU3Bizgb_hJbVWwEcpRiwmXkFu3yVOWeKmiBoCsq0QAvD_BwE

Same centres. You would be in real trouble if you had galvanic problems serious enough to justify a 4kg anode. The normal 2kg often lasts several years on a simple sailing boat protecting the propeller.

 

[Rhylsailer99]

Yes. Twice as big as you need. This is what is normally fitted marinesuperstore.com/anodes/zinc-hull-anodes/z-guard-zinc-pear-shaped-hull-anode-2-1kg-zg77kit?utm_source=google_shopping&utm_medium=pcn&utm_campaign=MSS&utm_term=ZG77KIT&gad_source=1&gclid=CjwKCAjw-JG5BhBZEiwAt7JR65rySGNCHLTL25AUMBSU3Bizgb_hJbVWwEcpRiwmXkFu3yVOWeKmiBoCsq0QAvD_BwE

Same centres. You would be in real trouble if you had galvanic problems serious enough to justify a 4kg anode. The normal 2kg often lasts several years on a simple sailing boat protecting the propeller.

That is what I fitted last time and lasted over a couple of years.

 

[Tranona]

In theory the bigger one will last twice as long and might be worth it if you intend keeping the boat afloat for several years. Have a look around and you will rarely se a large anode on a small sailing boat.

 

[NormanS]

As you are aware, the anode is bigger than required. BUT, you already have it, and the hole centres are OK, so why not just fit it?

 

[Tranona]

The centres are the same for both sizes (200mm), but the smaller pear shaped one has part of the strap exposed whereas the strap on the larger one is fully cast in. So they are physically interchangeable.

 

[Kwik Decision]

What's this anode bonded to / protecting? Assuming your boat is GRP, there's a good chance it's not needed. A shaft anode will look after your prop, and your through hulls will be fine provided they are DZR, bronze, or plastic.

 

[snowbird30ds]

If you're not worried about a little bit of extra drag just fit it, you already have it and there's no such thing as over protected.

 

[Neeves]

If you notice the extra weight and/or the increased drag - you are a VERY sensitive owner (sensitive in terms of sailing performance). As such you should be sailing (sorry, racing) a lightweight, twitchy and fast performance sailing yacht. If this is not you just fit the big anode (especially as it fits) as you will inevitably make a loss if you try to trade it in.

Hopefully it will lose the same weight per annum as the 2kg version and you can tell us the wear rate in 6 years time - I'll try to remember to add it it to my calendar so that I can post a reminder for you

Jonathan

 

[Tranona]

What's this anode bonded to / protecting? Assuming your boat is GRP, there's a good chance it's not needed. A shaft anode will look after your prop, and your through hulls will be fine provided they are DZR, bronze, or plastic.

There is no exposed shaft on his boat. A hull anode is usual and it is needed - he says it lasts a couple of years. An anode has no effect on through hulls even if they are plain 60/40 brass as they ar on most modern boats when new.

 

[Mister E]

As the boat is a bilge keel would it be correct to assume that the keels are metal?

 

[Tranona]

As the boat is a bilge keel would it be correct to assume that the keels are metal?

No - some boats have encapsulated ballast inside GRP mouldings. would not make any difference to anodes as they are not effective generally in preventing corrosion of metal keels. The only effective way of preventing corrosion on keels is to exclude water. A good coating system such as epoxy applied on a properly prepared surface can work.

 

[Rhylsailer99]

As the boat is a bilge keel would it be correct to assume that the keels are metal?

No they are encapsulated fiberglass keels and thru hulls are DZR fitted around 3 yrs old.

 

[Seastoke]

No they are encapsulated fiberglass keels and thru hulls are DZR fitted around 3 yrs old.

It’s a f in anode , put is on and polish that hull it’s dull.

 

[neil_s]

Fit the big one. I did and have forgotten how long it's been there!

 

[wingcommander]

There is no exposed shaft on his boat. A hull anode is usual and it is needed - he says it lasts a couple of years. An anode has no effect on through hulls even if they are plain 60/40 brass as they ar on most modern boats when new.

Similar case on my Vancouver 27. No shaft anode, so big hull anode showing signs of wear.Small rudder anode . However all my through hulls ( bronze ) are internally bonded . I have attempted to delve deeper and only find conflicting information . So I have left as found . Do you have a layman's reasoning for your statement.