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Cathodic protection?

Tin Diesel

Tin Diesel

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Houston, TX
With my boat in the shop for what I hope is a minor repair, I'm looking around for other ways to spend money on it (not)!

Its a 2007 Mercury I/O and has always been on a freshwater lake in Texas, and always stored out of the water - on a lift when my brother owned it, and now on a trailer.
When I got it in 2017, the skeg had some minor corrosion which I sanded down and fixed - no problems since.
There are some anodes on the stern drive - but I'm not an expert in these things.

Anyway, my question is this. We're thinking that a couple of times a year we may want to take the boat down to Clear Lake / Galveston Bay or Matagorda Bay (brackish water, I think, although Galveston Bay and Matagorda Bay will be more salt than Clear Lake).

Do I need to worry about adding cathodic protection - or maybe the Mercathode system? I know to rinse everything afterward, especially since my trailer isn't galvanized.
Any suggestions?
 
Nobody ever answered this, so I thought I would try again.
We're taking our boat to Orange Beach AL for a week this fall, where it will be in a rented boat slip in salt water for six days or operating in salt-water environments.

This is a fresh-water boat, and I know nothing about cathodic protection. There's a few anodes on it now.

Do I need to worry about this for just one week? I won't be able to flush everything until we get home to Houston but I know I need to do a thorough flush then.
Thanks.
 
I don't know anything about this....but i had a waverunner sitting on a jet port in salt water for 2 weeks a few years back.... the jet port was too short for my waverunner and the pump was sitting in the water. After the 2 weeks, there was some significant decay on the pump nozzle on nose cone (enough that they needed to be replaced). Somebody told me it was from stray current from an adjacent ski, but I'm not sure.

The point is, 1 week would likely be enough time to do some sort of damage...as for the prevention...I have no information for you.
 
They make a sacrificial zinc fish to hang over the side. I would guess it has some instructions- probably connected to motor or frame of boat? West marine has em.
I wouldn’t go without protection and use saltaway or equivalent every day out boating.
 
One thing to check - given your freshwater use you may have magnesium anodes which I think will sacrifice very quickly in salt water and potentially leave you exposed. Changing to aluminum will give you much more time and protection.

Your engine should already have aluminum anodes on them.

I caveat all of this to also say I am no expert.
 
Aluminum anodes won’t do anything for you, they will not be any more likely to corrode than the aluminum boat. Zinc is a better choice.
 
I always thought that Zinc was best for saltwater. Magnesium was best for freshwater and Aluminum does well in both?!?
 
That may have been the prevailing wisdom years ago but nowadays the recommendations are shifting. Not to say zincs won't do their job well, but Al alloys do it slightly better with more benefits. Suppsedly.

Lots of articles on this but this was short and sweet:

performancemetals.com

How Can an Aluminum Anode Protect an Aluminum Boat?

All too often we get the question, “How can an aluminum Anode protect an aluminum boat (or outdrive)?” In particular, there is the worry that they will not be suitable for salt water. Navalloy (aluminum) anodes are not like regular aluminum. They are made from a special alloy with indium. It’s a...
performancemetals.com performancemetals.com
 
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