Hunter Propeller Anode

[dlochner]

Definitely a Max Prop. Here's the anode you need:

Max Prop 63mm 2-Blade Zinc Anode (Z63R2)

Max Prop 63mm 2-Blade Zinc Anode (Z63R2)

boatzincs.com

Unfortunately, this anode is zinc and is pretty worthless in freshwater, which Lake Ontario is. I checked both the PYI site and Boatzincs.com and they do not show a magnesium or aluminum anode that will fit the prop. Which may be the reason there isn't one installed, but the PO installed a zinc shaft anode, which should be replaced with a AL or MG anode.

Best to call PYI and ask for a source for the right anode.

 

[Tally Ho]

How about this one?

Max Prop 63mm Universal Magnesium Anode (63M4-MG)

Max Prop 63mm Universal Magnesium Anode (63M4-MG)

boatzincs.com

I think that this one will work

Greg

 

[fstbttms]

How about this one?

Max Prop 63mm Universal Magnesium Anode (63M4-MG)

Max Prop 63mm Universal Magnesium Anode (63M4-MG)

boatzincs.com

I think that this one will work

That anode fits the 3-blade Max Prop. The OP has a 2-blade prop and the anode is different (see pix above.)

 

[Tally Ho]

That anode fits the 3-blade Max Prop. The OP has a 2-blade prop and the anode is different (see pix above.)

Good clarification…I saw “universal” and assumed it fit all Max-Props.

Greg

 

[FShab]

Thank you again everyone. Regarding the already installed shaft anode, although someone mentioned it's Zinc (and needs to be replaced by Magnesium) however, considering there is some wear and tear on it, doesn't it mean that it's actually functioning properly in fresh water and therefore a magnesium or Aluminum?

Thanks,
Fred

 

[dlochner]

Thank you again everyone. Regarding the already installed shaft anode, although someone mentioned it's Zinc (and needs to be replaced by Magnesium) however, considering there is some wear and tear on it, doesn't it mean that it's actually functioning properly in fresh water and therefore a magnesium or Aluminum?

Thanks,
Fred

Here are 3 anodes that were on my boat. From left to right, Zinc installed by the prior owner, aluminum after one season, magnesium after 2 seasons.In freshwater, zinc form a hard coating which insulates the zinc from the water rendering it ineffective.

 

[FShab]

Unfortunately, this anode is zinc and is pretty worthless in freshwater, which Lake Ontario is. I checked both the PYI site and Boatzincs.com and they do not show a magnesium or aluminum anode that will fit the prop. Which may be the reason there isn't one installed, but the PO installed a zinc shaft anode, which should be replaced with a AL or MG anode.

Best to call PYI and ask for a source for the right anode.

I spoke with PYI, they explained that they do not have Magnesium and the Aluminum one has 6 screws. As you mentioned, that's probably why the previous owner did not have any anode for the prop and used one for the shaft. Thanks again! Fred

 

[dlochner]

I spoke with PYI, they explained that they do not have Magnesium and the Aluminum one has 6 screws. As you mentioned, that's probably why the previous owner did not have any anode for the prop and used one for the shaft. Thanks again! Fred

That's unfortunate. Let's hope there is not stray current floating around your marina or in the boat. At each haul out closely inspect the prop look for any evidence of "pinking" where the blades show some pink or reddish coloring. If that does happen, it means the zinc in the bronze prop is leaching out which will make the prop brittle. Then it will be time for a new prop.

 

[Rich Stidger]

I have a suggestion. Buy a magnesium shaft anode and replace the shaft zinc. I assume that is possible.
For the prop magnesium anode, measure the inside diameter and the spacing of the two mounting bolts. Determine the size of the two mounting bolts. Armed with this info, goto a machine shop and have them make an adapter out of bronze stock that will fit inside of the prop and have the holes drilled for the two mounting screws. The center of this adapter will extend out beyond the prop and can be turned to your shaft diameter or smaller. This extension should be a standard shaft size. After securing this adapter on the prop, just attach a magnesium shaft anode.
Then, as required, just replace the anodes periodically.
If you have a friend with a metal lathe, it should be a 2-3 hour project to make the adapter.

 

[American_Mainsail]

That's unfortunate. Let's hope there is not stray current floating around your marina or in the boat. At each haul out closely inspect the prop look for any evidence of "pinking" where the blades show some pink or reddish coloring. If that does happen, it means the zinc in the bronze prop is leaching out which will make the prop brittle. Then it will be time for a new prop.

Is stay current corrosion something that you see commonly in fresh water? I was under the impression that it was more rare because fresh water has a hard time carrying current.

 

[Tally Ho]

Is stay current corrosion something that you see commonly in fresh water? I was under the impression that it was more rare because fresh water has a hard time carrying current.

I keep 2 magnesium shaft anodes on my boat at all times. One gets replaced each year (so 2 years old) and it is pretty deteriorated. I sail on Lake Michigan.

I had a fixed 2-blade prop until this year…I bought a new 3-blade Max-Prop EZ and it will be fitted with a magnesium cone anode.

Greg

 

[American_Mainsail]

I keep 2 magnesium shaft anodes on my boat at all times. One gets replaced each year (so 2 years old) and it is pretty deteriorated. I sail on Lake Michigan.

I had a fixed 2-blade prop until this year…I bought a new 3-blade Max-Prop EZ and it will be fitted with a magnesium cone anode.

Greg

Gotcha - thanks, Greg. I know that folks commonly use magnesium anodes on their boats in fresh water to protect against galvanic couple corrosion (although I suspect in fresh water this is more of a ritual than anything). In salt water, the voltage potential between stainless and bronze are just high enough to warrant a zinc or aluminum anode.

I was asking specifically about stray current corrosion in marinas being an issue in fresh water. Fresh water doesn't conduct much electricity (it's mostly devoid of electrolytes, which is why it's not very corrosive in the first place), so I'm wondering if anyone's had an issue with stray current corrosion in fresh water. I'm sure it happens, but I'm guessing it's rare. Inquiring minds want to know.

 

[dlochner]

Is stay current corrosion something that you see commonly in fresh water? I was under the impression that it was more rare because fresh water has a hard time carrying current.

There are 2 potential sources of stray current, between boats and within the boat. Between boat causes are more limited because of the low conductivity of fresh water, however it still occurs. The effective protective range of an anode in fresh water is a circle of about 10 foot diameter. My neighbors at the marina are about 4' and 6' away from me. Testing than anode protection I have in freshwater, I obtained a -.700v reading. In salt water it would have been about -.900v.

In Freshwater, between boat galvanic action is more limited than in salt water, but it still occurs.

 

[jssailem]

stray current corrosion in marinas being an issue in fresh water.

Simple answer is Yes. It can be an issue.

The current you are focused on is that generated by the boats (AC and DC wiring systems on the boats) and or the wiring system of the marina (AC wiring that is not up to code or not maintained).

Here is a thoughtful article about the subject (there are many).

Corrosion, Part 2: Stray Current | BoatTEST

boattest.com

The use of magnesium on the prop shaft in fresh water is a preventative measure. Yes fresh water is less conductive than sea water. That does not make it “non conductive”. There are still contaminates in fresh water that can act as electrolytes. More so around marinas than at the mouth of a fresh snow fed stream.

As was often said “an ounce of prevention is better than a pound of cure.” Your boat your choice.