Anode opinions

[KelseyB]

Alright so. 30' steel boat, has 2 weld-on zinc anodes near the transom (a few feet from the prop), and nothing on the propshaft because there isn't enough of it exposed for a clip-on. To mitigate the lack of propshaft anodes, the first time around I shelled out for propspeed. Two years later, propspeed is about 50% gone and there's some barnacle residue on the exposed spots, but no corrosion (it was also a brand new prop when the propspeed first went on). I'm close to relaunch, and am now trying to figure out what to do about the prop. The weld-on zincs are still about 80-90% there, so I was planning on brushing off the corrosion and keeping them. I was also planning on getting 1-2 of the clip-on zincs (usually shaped like a fish) for when she's docked. What do people think about the prop? I would really prefer not to go through the ordeal of cleaning it up and shelling out for propspeed again, but I also really don't think there's room for an anode on the shaft. Do y'all think the proximity of the weld-on anodes, plus extras while in port, will be enough to prevent corrosion? Or do I need to redo the propspeed? If I need to propspeed, any pro tips on ways to make the prep easier?

(Pictures show lack of room on the shaft for an anode, and proximity of weld-on zincs)

[JPA Cate]

First, Kelsey, you can buy a shaft zinc and with your hack saw cut off the ends with the screws, and use them on the shaft for a shaft zinc. Might need to wrap some seizing wire around it, and tuck the ends in so they don't scrag you when you're wiping the prop.

From the pictures, your propspeed does need renewing. It doesn't stop de-zincification, though, only makes it easy to keep the prop clean. The prep is painstaking, but not too awful, and it is the timing of the coats that is critical.

Ann

[Pauls]

You need a zinc on that propshaft. The hull zincs give, at best, a poor level of protection to your prop. Depending on the electrical isolation of your prop to the hulll, they may be giving you no protection at all.

[Uncle Bob]

Originally Posted by KelseyB

Alright so. 30' steel boat, has 2 weld-on zinc anodes near the transom (a few feet from the prop), and nothing on the propshaft because there isn't enough of it exposed for a clip-on. To mitigate the lack of propshaft anodes, the first time around I shelled out for propspeed. Two years later, propspeed is about 50% gone and there's some barnacle residue on the exposed spots, but no corrosion (it was also a brand new prop when the propspeed first went on). I'm close to relaunch, and am now trying to figure out what to do about the prop. The weld-on zincs are still about 80-90% there, so I was planning on brushing off the corrosion and keeping them. I was also planning on getting 1-2 of the clip-on zincs (usually shaped like a fish) for when she's docked. What do people think about the prop? I would really prefer not to go through the ordeal of cleaning it up and shelling out for propspeed again, but I also really don't think there's room for an anode on the shaft. Do y'all think the proximity of the weld-on anodes, plus extras while in port, will be enough to prevent corrosion? Or do I need to redo the propspeed? If I need to propspeed, any pro tips on ways to make the prep easier?

(Pictures show lack of room on the shaft for an anode, and proximity of weld-on zincs)

Hi, around here we can get shaft anodes that are thin and not rounded, research suppliers and I feel certain that you will find something that will fit.

[GordMay]

Originally Posted by KelseyB

... To mitigate the lack of propshaft anodes, the first time around I shelled out for propspeed. Two years later, propspeed is about 50% gone and there's some barnacle residue on the exposed spots, but no corrosion (it was also a brand new prop when the propspeed first went on). I'm close to relaunch, and am now trying to figure out what to do about the prop...

According to the Propspeed “Application Manual*”:
“Propspeed should last at least one year but many customers report up to two years of service.”
* ➥ https://propspeed.es/wp-content/uplo...CLINT-2015.pdf

[Sailmonkey]

There looks to be room on that shaft for a limited clearance shaft anode.

https://www.google.com/search?q=limi...&client=safari

And the prop speed isn’t an anode, it’s an anti foul. It will not prevent galvanic corrosion.

[noelex 77]

Originally Posted by Sailmonkey

There looks to be room on that shaft for a limited clearance shaft anode.

https://www.google.com/search?q=limi...&client=safari

And the prop speed isn’t an anode, it’s an anti foul. It will not prevent galvanic corrosion.

Agreed, but it will reduce galvanic corrosion.

[Sailmonkey]

Originally Posted by noelex 77

Agreed, but it will reduce galvanic corrosion.

So long as it is intact and isolating yes……

[noelex 77]

It does not have to be intact to reduce galvanic corrosion.

The relative surface area of the anode and cathode exposed to the electrolyte have a bearing on the amount of corrosion. Thus if the Propspeed was eroded from the tips of the propellor, but remained on other areas, it would still provide some reduction in the galvanic corrosion compared to an untreated prop.

If it was completely intact and isolating there would be no galvanic corrosion at all, but this is unrealistic over the long term.

[GordMay]

" Electrolysis of a vessel or even a vessel moored nearby can blow the coating system off the running gear. "
➥ https://propspeed.es/wp-content/uplo...CLINT-2015.pdf

[KelseyB]

Originally Posted by Sailmonkey

There looks to be room on that shaft for a limited clearance shaft anode.

https://www.google.com/search?q=limi...&client=safari

And the prop speed isn’t an anode, it’s an anti foul. It will not prevent galvanic corrosion.

This is a great idea... first time around I fit a normal clearance collar to it and it just barely didn't fit. Didn't even know they made low clearance ones.

True on the propspeed, but I agree with others that it helps a bit even if it's not its main purpose

[KelseyB]

Originally Posted by GordMay

According to the Propspeed “Application Manual*”:
“Propspeed should last at least one year but many customers report up to two years of service.”
* ➥ https://propspeed.es/wp-content/uplo...CLINT-2015.pdf

Agreed - wasn't trying to criticize propspeed, it worked great within its lifespan, and I was actively cruising for half of it and motoring a lot so I think it held up great. Just explaining the state it's in now

[fstbttms]

You can also use a prop nut-style anode.

[Rumrace]

I hope this helps. There is one out there to fit your prop shaft.

[Rumrace]

Two people with the same thought!
No my catalog ! 😂