electrolysis of aluminum boats

[harry2boat]

Could someone give me their experience with electorlysis corrision on aluminum boats?

 

[myalibi]

Re: electrolysis of aluminum boats

As long as you have good ZINCS you will have no problem. I have a 7 year old aluminum boat that sits in the salt water 5 months a year and I have no problems at all. Aluminum is prefered up here in Alaska because of the light weight and the money you save on fuel.

 

[harry2boat]

Re: electrolysis of aluminum boats

myalibi: <br />To everyone:<br />How long does it take for electolysis to take effect?<br />Will it be noticed in two or three days?<br />How and what size ZINCS would I need for a 20ft pontoon boat?

 

[BillP]

Re: electrolysis of aluminum boats

Saltwater = zinc<br />Freshwater = magnesium<br /><br />If the boat is used in freshwater use magnesium sacrificials. Aluminum is less noble than zinc when used in freshwater.<br /><br />Electrolysis starts the second you get disimilar metals together. What makes it fast or slow is how far they are apart on the nobility scale and if there are stray electrical currents from other sources. I've seen galvanized bolts get totally wasted in 6 months that didn't have zincs...in a marina with stray currents. Aluminum would have lasted only a month or two. You won't see it in a few days or few weeks unless REALLY extreme conditons exist...not likely.

 

[crazy charlie]

Re: electrolysis of aluminum boats

I owned a 25ft alum cabin cruiser years back that stayed in salt water for the season.The biggest factors with electrolysis are using the correct paint on the bottom.use ONLY paint recommended for aluminum.The marina you are in will play a big role if many boats are plugged in to electric.If you are near a wood boat that is plugged in to electric.All are factors that will accelerate electrolysis.I have seen pea sized holes in boats within a week.Salt water will react much more severly than fresh.Make sure your zincs are bare cleaned metal to metal and tight.Charlie

 

[jyasaki]

Re: electrolysis of aluminum boats

Originally posted by BillP:<br />Saltwater = zinc<br />Freshwater = magnesium<br />

Okay; what if you're going to be using the boat in both freshwater and salt? Do you need to be swapping anodes every time? Can you run both together?<br /><br />jky

 

[Capn Mike]

Re: electrolysis of aluminum boats

Go for the zinc. There won't be much electrolysis in fresh water anyway, unless you're in a hot marina, in which case the zinc should work OK for that. <br />I have a fiberglass boat in a sort-of-hot marina, and an OB. The original motor zincs were zinc, and when they were used up, I switched to magnesium. Didn't see much happening, except for a zinc that was still zinc, so I switched everything back to zinc.

 

[BillP]

Re: electrolysis of aluminum boats

Originally posted by jky:<br />

Originally posted by BillP:<br />Saltwater = zinc<br />Freshwater = magnesium<br />

Okay; what if you're going to be using the boat in both freshwater and salt? Do you need to be swapping anodes every time? Can you run both together?<br /><br />jky

jky...I don't know that one and don't have a nobility scale handy to look it up. Running both would probably work but the sacrificials would waste faster.