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Anode Replacement

Posted: May 14th, 2018, 2:50 pm
by nautiyachti
I have an 06 41 CMY and my trim tab anodes need to be replaced ( see attached). Can anyone tell me the part numbers for these? I'm in freshwater so I believe I need magnesium.

I also attached a photo of the hull anode which I believe is ok and does not need changing, what do you folks think?

Thanks

Re: Anode Replacement

Posted: May 14th, 2018, 3:41 pm
by tomschauer
Looks like you can wire brush the hull anode and get at least one more season out of it.
Determine it is zinc, aluminum or magnesium. If its zinc you may want to replace it with the others as they should all be the same.

I am in mostly fresh water but often travel into brackish water. I use aluminum anodes.

Re: Anode Replacement

Posted: May 14th, 2018, 3:43 pm
by Midnightsun
R-3M, You need 2 of these. http://www.boatzincs.com/rudder-sizes-magnesium.html

ZC-406M, You need 1 of these. http://www.boatzincs.com/ZC-406M.html

No bother price shopping as I already did it for you. :-D

Carver does not bother to ask where the boat is going to be used, they just deliver all of them with zinc however going to magnesium for fresh water is the correct route for the best protection.

Re: Anode Replacement

Posted: May 14th, 2018, 6:26 pm
by bud37
MSun hit it on the nose there.....lake Simcoe, use Mg anodes.....those in your pics look like they are Zinc , but you can tell by removing them and comparing weight.....be sure to change them all, so if you have them on the prop shafts, change them as well so all your anodes are the same material. You can tell when you take them off...the zinc is heavy as compared to either the Mg or Al which are quite light.......good luck man and thank you for being a good dock neighbour....... :beergood:

Re: Anode Replacement

Posted: May 14th, 2018, 10:03 pm
by Viper
Looks like your anodes are zinc so they're not doing a thing for you.

I only use aluminum in fresh water inboard applications now. Ya magnesium is more active and is great for aluminum sterndrives but considering the running gear on inboard applications is stainless and bronze, aluminum is active enough for those metals, will last longer than magnesium, and is less expensive.

Re: Anode Replacement

Posted: May 15th, 2018, 4:48 am
by Midnightsun
Aluminum will work well however in my case I am sure the all aluminum underwater lights will be happy I used the Magnesium. ;-) That being said, the cost difference for the entire set is only $30 between alu and mag and as far as boat dollars go that is nothing. Magnesium will deteriorate faster however there is no denying it does provide the ultimate protection for boats in fresh. I cannot comment on the longevity since I just bolted those Magnesium units on last week!

Then again Carver put useless zinc on my fresh water boat which have been in place for 10 years and there are no signs of corrosion that I can see. Maybe I was lucky to not be in a hot marina/environment or maybe the Charles isolation transformer Carver used just works very well or maybe a combo of both. As Viper said, running gear is stainless and bronze unlike problematic outdrives that are very prone to this problem. As a matter of fact, I cannot recall reading about corrosion issues on inboard boats like we have here.

Re: Anode Replacement

Posted: May 15th, 2018, 7:45 am
by bud37
Hans ,chances are your boat was being protected by your galvanic isolators and that transformer you mention....remember anodes protect against DC leakage corrosion, you may be fine for years then all it takes is a DC fault ( bilge pump wet wiring etc) and there can be tremendous damage in a short period of time, even from someone else's boat nearby, that is when the isolator comes into play.
My boat was the same, had zinc on it , looked like brand new ,on the first year I changed to the correct anodes you could see evidence of activity.....now the trick here is to get all your dockmates on the bandwagon so you are not protecting everyone else.

Edit...to add...there is no possible way to explain this fully in just a few short sentences, but the overall idea is here. That said, suffice it to say ,just protect your boat with the correct anodes for the areas that you boat in and in most cases all should be well.

Re: Anode Replacement

Posted: May 15th, 2018, 12:57 pm
by Viper
Ya the trick is to protect based on your particular application. For instance, while I use aluminum on inboards now, if the application has aluminum hardware in the water such as a hydraulic swim platform, the choice is magnesium. Your aluminum lights would definitely benefit from the mags. As Bud said though, with magnesium, unless everybody else around you is using the same, you will lose a lot of material to them. Having said that, it's pretty typical to replace mags every year anyway because they're so active. They may look okay at the end of the season but consider that they'd have to make it through another full season with enough mass part way through to have any affect. The surprising thing you said was that the difference in cost for all the anodes is only $30. That's not what I'm used to seeing but I haven't used mags in a long time so pricing may have changed.

Re: Anode Replacement

Posted: May 15th, 2018, 1:44 pm
by Midnightsun
I am the only one that has shore power on my dock so chances are they should not deteriorate all that fast due to stray currents. Just a few 14-16' day boats behind me with no power or water available at those fingers. Curious to see the wear after the season is over.

Pricing between the zinc and aluminum was about $2 cheaper for the entire set for the zinc compared to aluminum and like I said about $30 more for the Mag over the Alu. All in all it is not very expensive and very easy to change out when on the hard. Even rather easy to do with a mask and a deep breath while in the water if push comes to shove.

Image

Re: Anode Replacement

Posted: May 16th, 2018, 11:44 am
by nautiyachti
Thanks for all your responses folks, much appreciated.

MSun, you say I need 2 x R-3M but it looks like they come as a pair? Wouldn't I just need 1 and I'd have to get a SS nut and bolt to install the second on the trim tab?