My boat is in freshwater. At the end of summer I noticed that my zinc on my prop shaft was almost 1/2 gone and planned to replace it. Well the water got too cold so I bolted an aluminum plate to a copper wire and attached it to my backstay which is bonded to everything metal in the boat. I was nervous about aluminum so I bolted a zinc to the mess just to be sure. After two weeks the aluminum is showing signs of corrosion but the zinc looks good as new. Now I am thinking about using aluminum on my prop shaft. I guess that another option is magnesium but since I plan to return to saltwater I am thinking about staying with aluminum or zinc. What are others using for anodes???
Zinc or Aluminum???
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My boat is in freshwater. At the end of summer I noticed that my zinc on my prop shaft was almost 1/2 gone and planned to replace it. Well the water got too cold so I bolted an aluminum plate to a copper wire and attached it to my backstay which is bonded to everything metal in the boat. I was nervous about aluminum so I bolted a zinc to the mess just to be sure. After two weeks the aluminum is showing signs of corrosion but the zinc looks good as new. Now I am thinking about using aluminum on my prop shaft. I guess that another option is magnesium but since I plan to return to saltwater I am thinking about staying with aluminum or zinc. What are others using for anodes???
Zink
better go before the aluminum , or there is a hole lot of outboard's and stern drives in trouble.
better go before the aluminum , or there is a hole lot of outboard's and stern drives in trouble.
Zink
better go before the aluminum , or there is a hole lot of outboard's and stern drives in trouble.
better go before the aluminum , or there is a hole lot of outboard's and stern drives in trouble.
actually they are in trouble
Zinc won't "go" before aluminum in fresh water. Aluminum will corrode quite quickly which is why it is second only to magnesium as a good fresh water anode. The difference is that all outboards and sterndrives are primed and painted which protects them. Just take a look next time you visit a chandlery near fresh water to see all the aluminum anodes.
Zinc won't "go" before aluminum in fresh water. Aluminum will corrode quite quickly which is why it is second only to magnesium as a good fresh water anode. The difference is that all outboards and sterndrives are primed and painted which protects them. Just take a look next time you visit a chandlery near fresh water to see all the aluminum anodes.
actually they are in trouble
Zinc won't "go" before aluminum in fresh water. Aluminum will corrode quite quickly which is why it is second only to magnesium as a good fresh water anode. The difference is that all outboards and sterndrives are primed and painted which protects them. Just take a look next time you visit a chandlery near fresh water to see all the aluminum anodes.
Zinc won't "go" before aluminum in fresh water. Aluminum will corrode quite quickly which is why it is second only to magnesium as a good fresh water anode. The difference is that all outboards and sterndrives are primed and painted which protects them. Just take a look next time you visit a chandlery near fresh water to see all the aluminum anodes.
Still learning everyday!!
thanks: PS: I only have boats moored in salt water so I never new that.
thanks: PS: I only have boats moored in salt water so I never new that.
Still learning everyday!!
thanks: PS: I only have boats moored in salt water so I never new that.
thanks: PS: I only have boats moored in salt water so I never new that.
Aluminum Alloys
I think that a lot of stuff is actually aluminum alloys with more or less galvanic action. looking around after a google search it seems that aluminum is the anode of choice now. Works well in freshwater or saltwater and it is non toxic compared to zinc. It seems that aluminum is superior to zinc in freshwater because zinc can form a coating that stops it from corrodeing and protecting.
I think that a lot of stuff is actually aluminum alloys with more or less galvanic action. looking around after a google search it seems that aluminum is the anode of choice now. Works well in freshwater or saltwater and it is non toxic compared to zinc. It seems that aluminum is superior to zinc in freshwater because zinc can form a coating that stops it from corrodeing and protecting.
Aluminum Alloys
I think that a lot of stuff is actually aluminum alloys with more or less galvanic action. looking around after a google search it seems that aluminum is the anode of choice now. Works well in freshwater or saltwater and it is non toxic compared to zinc. It seems that aluminum is superior to zinc in freshwater because zinc can form a coating that stops it from corrodeing and protecting.
I think that a lot of stuff is actually aluminum alloys with more or less galvanic action. looking around after a google search it seems that aluminum is the anode of choice now. Works well in freshwater or saltwater and it is non toxic compared to zinc. It seems that aluminum is superior to zinc in freshwater because zinc can form a coating that stops it from corrodeing and protecting.
Galvanic Isolator
Most new boats are equiped with Galvanic Isolator. You can mke one yourself by joining two high current (30A+) diodes in series forward and another two in reverse. The voltage drop of 1.4V will stop galvanic action. Mount the diodes on a heat sink able to take at least 30A. Best to just buy one for around $100 and install it on the ground wire to shore power. I have one for a few years with zero galvanic corrosion. www.boatus.com/seaworthy/galvanic/default.asp www.yandina.com/galvanicIsolator.htm
Most new boats are equiped with Galvanic Isolator. You can mke one yourself by joining two high current (30A+) diodes in series forward and another two in reverse. The voltage drop of 1.4V will stop galvanic action. Mount the diodes on a heat sink able to take at least 30A. Best to just buy one for around $100 and install it on the ground wire to shore power. I have one for a few years with zero galvanic corrosion. www.boatus.com/seaworthy/galvanic/default.asp www.yandina.com/galvanicIsolator.htm
Galvanic Isolator
Most new boats are equiped with Galvanic Isolator. You can mke one yourself by joining two high current (30A+) diodes in series forward and another two in reverse. The voltage drop of 1.4V will stop galvanic action. Mount the diodes on a heat sink able to take at least 30A. Best to just buy one for around $100 and install it on the ground wire to shore power. I have one for a few years with zero galvanic corrosion. www.boatus.com/seaworthy/galvanic/default.asp www.yandina.com/galvanicIsolator.htm
Most new boats are equiped with Galvanic Isolator. You can mke one yourself by joining two high current (30A+) diodes in series forward and another two in reverse. The voltage drop of 1.4V will stop galvanic action. Mount the diodes on a heat sink able to take at least 30A. Best to just buy one for around $100 and install it on the ground wire to shore power. I have one for a few years with zero galvanic corrosion. www.boatus.com/seaworthy/galvanic/default.asp www.yandina.com/galvanicIsolator.htm
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