Zinc anodes

[Rhino]

I have seen many post about changing the mag anode to zinc but can find where to order all 3 from.. Help?

 

[zipper]

@Rhino You can try Yamaha Sports Plaza https://www.yamahasportsplaza.com/oemparts/a/yam/50855540f8700223282324bf/jet-unit-3 Part no. 11 (2x) and part no. 25, 29. Does not specify if zinc or mag. you might have to call to verify.

 

[druppert]

Great question. Following for a solution as well

 

[haknslash]

What type of water are you boating in? Do you store your boat near shore power or where electrical current could be? If boating in freshwater magnesium is what you'll want. If you use zinc in fresh water it's just going to oxidize on the outside preventing the zinc from doing it's job. If you're in brackish go with zinc.

 

[druppert]

I split my time about 70/30 salt/fresh water. The mag anode appears to work as it’s pretty pitted & there’s no corrosion whatsoever anywhere else after 100 hrs but I was going to leave the magnesium anode on one side of the pump and add a zinc on the other side. Any thoughts on this? Would the different types of anodes interfere with each other?

 

[druppert]

@haknslash would you mind elaborating on the question about electricity? I don’t understand much about the chemistry at play.

 

[Rhino]

What type of water are you boating in? Do you store your boat near shore power or where electrical current could be? If boating in freshwater magnesium is what you'll want. If you use zinc in fresh water it's just going to oxidize on the outside preventing the zinc from doing it's job. If you're in brackish go with zinc.

Brackish mostly

 

[haknslash]

@haknslash would you mind elaborating on the question about electricity? I don’t understand much about the chemistry at play.

This is a nice article for ya http://www.boatsafe.com/nauticalknowhow/012000tip3.htm. Just pretend where they mention props and other components of a "non-jet" boat they are talking about your pump housing instead

Edit - this is also a good read on different types of anodes https://www.boatingmag.com/how-to/choosing-right-sacrificial-anode

 

[zipper]

Here is more info...


And a link to Electrolysis, galvanic and stray current corrosion http://www.pcmarinesurveys.com/AC DC electrolysis.htm.

Edit: add another link, http://www.pcmarinesurveys.com/Anodes, Zincs, Aluminum, Magnesium and Boat Corrosion.htm

 

[Cobra Jet Steering LLC]

you can adapt just about any zinc and there are empty mounting castings on the right side of your pump so adding one is easy just remember to leave room for the steering nozzle to turn fully.

 

[druppert]

In case anyone needs measurements mine (2017 19’) is 4 1/2 x 2 x 9/16 with a 3 1/8” bolt pattern. Old threads on this topic recommend boatzincs.com. I found a couple of options:
1 of these:
http://www.boatzincs.com/hj-104634-specs.html
OR
2 of these:
http://www.boatzincs.com/h2b2.html

The mounting point has a sufficient base where the button type could be mounted independently from one another and give roughly the same surface area as the stock rectangle anode. The 1st one is a bit narrower and shorter than stock but it’s also slightly thicker. I think I’m going to order the 1st one.

 

[Cobra Jet Steering LLC]

Remember you can always make an aluminum plate and mount it to the bosses on the pump with the anode mounted to the plate so obviously you drill the appropriate mounting holes for that anode to go on the plate etc. allowing you flexibility to mount any anode any place convenient. I have several

 

[druppert]

From the links everyone has shared the magnesium is the most aggressive, zinc is the least aggressive, & the aluminum is in between. The boating magazine cautions against wet slipping a boat equipped with magnesium but doesn’t describe what “a catastrophe” entails. I guess they were preoccupied with their next food pun. What is the risk of using an overly aggressive type of anode other than a short lifespan? I can live with that as the magnesium anodes are a hell of a lot easier to get.