What type of anodes?

[Chris_d]

I very much doubt the outdrives are pure aluminium, more likely a stronger aluminium/copper alloy, but yes the trick is to use a material for the anode that will erode at a faster rate than the items you are trying to protect. I must admit that I always thought that magnesium was the way to go in fresh water

Nothing wrong with Mag but the world moves on, for outdrives Ali works and is cheaper than Mag and works well in saltwater too.

 

[russ]

The Ali ones are an alloy and not pure aluminium so they are less noble than the outdrives and react first, i've used them sucessfully for at least 5 years on the non tidal.

A 2nd marine company has also told me they now fit ali anodes to fresh water boats and no longer use mag.
I have agreed for them to fit the Ali ones and I'll compare on next years lift out.

 

[rosssavage]

Perhaps, just perhaps, for this one time in history, I MAY be wrong.

Did investigate Ali anodes for my boat three yrs ago, but couldn't find them in the right shape for the boat. Just fitted a fresh set of mags - maybe try Ali next year....

 

[russ]

Perhaps, just perhaps, for this one time in history, I MAY be wrong.

Did investigate Ali anodes for my boat three yrs ago, but couldn't find them in the right shape for the boat. Just fitted a fresh set of mags - maybe try Ali next year....

Will let you know next year Ross how well they are working.
Is not correct that the quicker they erode the better they are protecting the boat?

 

[CX54WEK]

We have switched to ali's on our sterndrive boat. Our mags we struggling to last a year out as we are always switching between fresh, brackish and salt water. Four weeks in salt water each year was doing them no favours.

This will be the first year we have switched them so it will be interesting to see how they fair up.