Anode Zincs last 3 months

[Norm and Candy]

Must replace aluminum anodes every 3 months. I am first owner to keep boat in salt water. It is a 1995 Sea
Ray 290 Sundancer with 2 Mercruiser 4.3LX, Alpha 1, gen 2 drives with Stainless Steel props. Electrican tested Galvanic isolator and used Reference Electrode to check boat systems and Dock location. All test readings found were OK and anodes were not painted. Boat does not have Mercathodes. I had SS props painted with special prop paint to see if that would help, but it did not. I understand that most boats with my configuration are not having this problem if they have aluminum props. Should I exchange props to aluminum since I could get and even exchange or must I install Mercathodes (expensive)or do both. Open for any recommendations. Also, where can you purchase the best( not cheapest) most realiable aluminum anodes.

 

[Henry Boyd]

First off welcome to CSR.

Getting rid of the SS props will be an improvement from a corrosion standpoint. But there may be another issue. You say you are the first owner to use the boat in saltwater. Did you replace the anodes, or continue to use the anodes that were on the boat? You called the anodes 'zincs'. Anodes are often referred to as 'zincs' when in fact they can be other metals. For fresh water I believe your boat should have had magnesium, and in salt water aluminum. Using magnesium in salt water would lead to rapid deterioration, and may be the cause. I'm assuming you have swapped out the old anodes with new zinc anodes. Why don't you give those a try before jumping into expensive options like Mercathodes and prop swaps?

The other thing to consider is that full time use in salt water for sterndrives in warm climates is kind of a losing battle. You may need to find a location where the boat can be on a lift, or out of water storage for when you are not using it.

Henry

 

[IanBat]

Mine gets around 4-5 months, similar set-up. PO is a Volvo dealer and a friend, so had informed me that was the timeframe.
It is due now, working up the motivation to back it onto a sandbar at the right Point of the IDE and swap them over. Basically need doing in between antifoul time.
He I'd suggest the other day that if I swap,over to aluminum props, I will get through to antifoul time


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[Lord Farringdon]

As Henry said, you need to be sure you have zincs and not magnesium for freshwater. Not quite the same configuration as yours I know, but this is picture of my zinc anode after 9 months in temperate water. Yes, it should have been replaced earlier but this is what I found when I pulled the boat 6 months after purchase. I change my zincs every six months and I know I could go a couple of months longer if I had to.

By the way, I have stainless steel duo props with propspeed applied. Welcome to CSR :grin:



Terry.

 

[Norm and Candy]

Thank you. This is the second pull out with new Zincs from our maint dept, they only install for salt water so I am sure they are correct. The paint I put on the props isw also Propspeed. My sincs look like yours after 3 months.

 

[Norm and Candy]

Thank you, it is good to know that I am not alone. I am going to have to start putting them on myself.

 

[Norm and Candy]

Thank you, I did have new zincs installed before I put the boat in. This is the second pull out with same results in 3 months.

 

[masilobes]

i am in salt water on a mooring and have always used zinc zincs until this year. was there a change to use aluminum zincs? i have always done my research and i buy them from boatzincs.com which i thought up to this year said in salt use zinc. now when you use the're chart it says to use aluminum which i switched to but they already need to be replaced. zinc would have lasted me the whole season. is something wrong? the only difference was that i had my stainless props that were painted sent out to be refinished and i never painted them when i got them back.