Shaft Anode and Prop Anode ?

[Weyalan]

Having just replaced the prop and shaft on Insatiable, I kinda want to protect my investment, so:

Do I need an anode on the shaft and on the propeller?
Even if I don't need both, is there any harm in having both?
If there is no harn, would you fit both just in case one falls off?

[Bash]

Not only would I fit both, but I keep two zincs on the shaft (and one on the prop.)

Cheapest insurance policy you'll ever get on a boat.

Install the second shaft zinc a month or two after you've installed the first. That way you only need to change the thin one.

[Jim Cate]

G'Day Patrick,

So, did you get the Flex0fold? We do use both a prop and a shaft anode on ours, but on several occasions the prop anode has gone away and we've not had any electrolysis issues (touch wood).

If you do have a FOF, you may soon get tired of paying for their proprietary anodes. I replaced the allen head cap screws that hold the cover plate over the gears (that's the plate that the anode actually is bolted to) with countersunk screws, leaving a nice flat surface. One can then use cheap "button" zincs, held on with the central screw. They are not as massive as the FOF ones, but cost about 1/10th as much, and are easy to replace in the water.

Cheers,

Jim and Ann s/v Insatiable II lying Cairns, Qld Oz (where it is 30 deg every day)

[Weyalan]

Thanks for that, Jim.

Yeah, we did go with the Flexofold, which we fitted this weekend. Early to tell, but the motoring performance seems excellent. We only motored across the Derwent from where we slipped back to Bellerive, but we had the revs relatively low (because I was fiddling with the gland nut on the stuffing box, seeing as we replaced the packing while we were fitting the new shaft and prop... but even at low revs we were motoring much faster than usual, and with less vibration too. Happy, we are!

[fstbttms]

Originally Posted by Bash

Not only would I fit both, but I keep two zincs on the shaft (and one on the prop.)

Cheapest insurance policy you'll ever get on a boat.

Finally, we agree on something.

[Weyalan]

Thanks for the input people. I will add the shaft anode at first opportunity.

[rusky]

It is good advice to have an anode on both shaft and prop, but look at the total amount of zinc you have on the boat first. What is Insiatable made of.

I saw a steely with too much zinc, it caused galvanic problems - the boat was a battery!

Also, have them easy to tighten whilst in the water (I did not say underway!!) aka with an allen key, not phillips head and nut.

[Weyalan]

Insatiable is fibreglass / kevlar

[rusky]

Originally Posted by Weyalan

Insatiable is fibreglass / kevlar

From the photos, she looks a beauty.

[EBCAU]

When I was in the process of purchasing (as a complete newbie) my fibreglass forty footer the vendor chose to replace the prop shaft anode during my surveyor's inspection. He left the half used one on the shaft with the new one beside it.

My surveyor said that this was a no-no as it was possible to over zinc and cause damage. This resulted in an altercation between the two parties only resolved by the broker removing the vendor from the scene!

During the subsequent seven years of ownership I came to hold the opinion the vendor was a less than quality individual and maintainence not his strong point. Consequently I have only ever run one anode as stipulated by the surveyor. However, the idea of running two at different stages of consumption certainly appeals because I have had the single one come off.

What are opinions on this please?

[fstbttms]

While it is certainly possible to over-zinc, it typically is going to take a lot more than two shaft zincs to do it. Two shaft zincs is a very common arrangement and to argue that there is an inherent problem with that arragement is indicative of a high degree of ignorance, IMHO.

[GordMay]

Originally Posted by fstbttms

While it is certainly possible to over-zinc, it typically is going to take a lot more than two shaft zincs to do it. Two shaft zincs is a very common arrangement ...

indeed.

[SuenosAzules]

I agree fstbttms.. Two zincs is better than one. No worry about over zincing with two.

[Weyalan]

Originally Posted by rusky

From the photos, she looks a beauty.

Why thank you
She isn't to everybody's taste, nor would many people choose an IOR 1-tonner as their short-handed cruising boat of choice, but she's bought 'n paid for and a whole lotta boat for not a lot of money.

I would probably swap her for a decent Peterson 46' though!