Anode questions

[jennis9]

How do you properly care for anodes? How many do you need?

Also, I read somewhere about bottom paint and anodes. Can't find the post - are you not supposed to paint behind or near an anode? Our boat has paint up to it. we are in freshwater - aluminum boat, I/O.

 

[bhammer]

Re: Anode questions

The amount depends on the boat and what type of water and whether it is an active or passive system. On my boat, I have one on the drive and the tilt rams. You should never paint them or under the mounting surface...

 

[jennis9]

Re: Anode questions

how many do you need on a 20foot boat?

 

[tommays]

Re: Anode questions

It depends

Things like and SS prop and SS trim tabs will need more protection that the same boat without those parts


The standard sets on a Alpha 1 GEN II should provide plenty of protection under normal conditions


You need to get the correct type as they have freshwater and saltwater materials AND you need to be carefull of brand X stuff as it may have a marginal material that will not provide the proper protection

 

[BillP]

Re: Anode questions

Magnesium is for fresh water. Zinc for salt. If you use zinc in freshwater the aluminum will be the anode. The anode has to make metal to metal contact to work properly. Don't paint under or over the anode.

Don't worry about active or passive stuff, it isn't applicable to small trailer boats...but they are passive.
bp

 

[jennis9]

Re: Anode questions

do i need to sand it if it looks chalky?

sorry if these are silly questions, I really have no idea...

 

[Knot Waiting]

Re: Anode questions

do i need to sand it if it looks chalky?

sorry if these are silly questions, I really have no idea...

It is a good idea to clean them up every once and a while. Sand paper or wire brush work well. The purpose of an anode is to protect the drive from electrolosis. Stray electricity can dissolve the drive, the anodes are there to dissolve first so the drive doesnt. An anode that has been painted or is filthy does not have proper contact with the water and cannot do its job effectively. As stated most smaller boats use a passive system that consists of anywhere from 2-5 anodes. Magnesium is for freshwater and zinc for salt.

 

[heymhk2]

Re: Anode questions

Hi, I've primed and soon will be ready to apply bottom paint to the Aluminum bracket that holds my engines. Do I have to remove the primer from the area that the anodes will be making contact with the bracket? Or can I go ahead and apply the bottom paint then put the anodes in place?

Sorry if im asking questions that have already been answered, I've read the previous posts in this thread but I just want to be 100% sure.