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Pontoon Pitting

Didn't understand the situation. Thanks for the clarification JeffS
 
There is a lot if good info here on electricity and water or shore power issues but do still check out your own boat for electrical issues if it is still under warranty. The engine should have anodes as well. They are cheap to put on the boat anyhow.
 
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Since when do pontoons have sacrificial anodes. They are on the lower unit of my Honda bur there's none on the toons. And the ones on the motor still look brand new.
 
Would Shark-hide prevent the pitting that occurs from stray voltage?  Just wondering since our boat is due to arrive soon and if this is an issue in any way/shape/form, I want to be proactive in preventing this.  

Thanks!
 
PutterLaz said:
Can you explain what would cause an "anode" issue?
Click to expand...
I just went and looked at my anodes and after 3yrs, and over 100hrs on the meter, my anodes look new.

So, there are 2 types of corrosion the anodes protect against, galvanic corrosion and electrolytic corrosion.

Galvanic corrosion is the reaction between dissimilar metals, such as steel vs aluminum. Some of you may be familiar with this from working on cars and trucks. That steel bolt that was threaded into that aluminum housing has all this powdery white stuff on it, and was a bugger to get out. Galvanic corrosion.

Electrolytic corrosion happens when there is an electric current added to the water, this is an electro-mechanical reaction that causes the metal parts to decompose. Well, PutterLaz has shown us that example.

So, since our simple pontoons don't have ANY alternating current systems, i.e. generators, air conditioners etc, and our direct current systems should not be grounded in any way to the "chassis" of the boat, and most of us boat in fresh water................

what else could be causing this condition on PutterLaz's toons?

I am not trying to stir up trouble here, or to cry wolf, but if it where my boat i would want to find the answer to this problem, and even though it isn't mine, well, inquiring minds want to know :)
 
Your pontoons are indeed electrically bound to the electrical system on your boat. Or at least it should be. Look under your motor mount, the anode should be in a bracket that is secured to the pontoon, and there should be a binding wire attached to the bracket and up to the motor.

Putterlaz's condition was probably caused by another boat nearby. If I were to guess at an exact culprit, I would put odds on the possibility there is a fishing boat nearby, with lots of trolling motors and electronics, powered by a bank of house batteries, one with a broken plate but unnoticed because there are 2 or more tied together. My bet is the boat has an onboard charger, and the owner probably plugs it in after every outing, and doesn't lift the motor out of the water when charging.

Just a hunch though. I don't dock near fishing boats that are charging. They are notorious stray current producers.

On bigger lakes like Tablerock or similar, it is also worth paying attention to boats around where you intend to dock. If you see a boat on a lift next dock over with a pitted lower unit or a corroded prop...don't dock there. No different than not parking next to the car with a thousand door dings.
 
Jeff is right on.

Alternators produce AC current that is converted to DC through diodes, a bad diode in the alternator can cause all sorts of small issues over time. Plus any type of electrical current will cause electrolysis. Could be caused by something as simple as a small amount of moisture on top of the battery or any sort of material that will conduct current between battery posts unless they are 100% clean and dry. Remember we are talking miliamps over time to cause this.
 
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Would this show up on an aluminum lift? I would assume yes but curious to see if anyone has observed it there.
 
Stupid question incoming:  If we didn't get the saltwater package, then we don't have anodes on our boats?  Or do all Bennington's have them and I just need to look under the toons to see them?
 
The only ones i could find are on the motor bracket, nothing on the toons themselves.

I do not have the saltwater package.

Lakeliving, i would assume so, if portions of the lift are in the water all the time.
 
Dissimilar metals are a culprit as well. Stainless steel and aluminum for example. Leaving a boat in the water without any protection is not a good idea. While I boated on Cape Cod and was in a marina at a Yacht Club I always checked the Zink's. Not once a year but every week. Lose a Zink Lose your boat. The shafts each had Zink's, the stern of the boat had a bracket with a Zink  Pitting becomes a hole. the hole becomes a leak. guess how the boat will look when you get back to it. The other problem can be a brine in the water, salt mixed with something can create a chemical reaction as well.

Problems like these are taught at many boating classes. A good class will not only have boat handling, but reading navigation aids, Knot tying, Chart reading, and care of your boat.
 
Hey there everyone. One more from me to add to what highpond wrote.

There are lots of different types of boating, and different types have different issues that are common. What Highpond wrote, and what I wrote about earlier...yachts in marinas... That's a very specific type of boating and sac-anodes are paramount in that type of boating. The yachts are all connected to shore power...often a big 30A - 100A 220V feed, powering everything from A/C to outlets to battery chargers and power-flushing heads. There are through-hull brass fittings grounded to the electrical system that leak current. It is what it is. And all of the running gear is underwater with multiple types of metal. And the majority of those vessels are in salt water. 

What we do with pontoon boats, for the most part...is not that.

Beyond yachts in marinas connected to shore power, there are trailer boaters and live-on-the-lakers. The live-on-the-lakers with expensive boats, typically have lifts. On top of that, the live-on-the-lakers aren't usually densely packed with boat on top of boat on top of boat. Since distance and proximity to the a current-leak is a factor (leaking current seeks the shortest path of least resistance to ground), it's usually not an issue.

For the trailer boaters - they don't usually boat near where current is leaking for a period long enough to experience problems. So for them...it's not an issue.

For boats that aren't vulnerable to galvanic or electrolytic corrosion, it's not unreasonable to think that anodes will last decades. For boats that are vulnerable for whatever reason, they may not last a season.

It's all about how you boat and where. I have to think, the vast majority of boaters on this forum have nothing to worry about. The boats are either on lifts, or spaced far enough apart on a lake, or on a trailer. Be knowledgeable about what can happen, but don't worry too much about it. The only time in the last year, that I even considered electrolytic corrosion...We had the Bennington at the marina where we used to keep our cruiser, for a weekend of fun with old friends. I intentionally did not plug in my battery charger at night as that would connect my boat to the ground on the dock and close the loop making my boat a great attractant to stray current. That was my whole thought process and solution. I worried about for 2 - 3 seconds.

Stay away from bass boats that are plugged in - especially the old crappy and dirty ones. 

Don't sandwich your boat for extended periods between sail boats and motor yachts (even small ones) that are connected to shore power.

And if you plan to dock for a while at a busy dock, look for a boat on a lift somewhere near where you plan to dock and look at their running gear - if it's corroded and pitted...don't dock there.

Cheers everyone.

-Jeff
 
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JeffS

Stated my reality precisely

Very fortunate to be on the lake front with no boats nearby

Still it is always important to keep electricity off the dock

I placed spotlights on the deck instead of dock for this reason

No radios with electricity placed on dock 

The further away electricity is placed from water the better

 
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We have shore power to our dock and boathouses. The most important thing is to guard the wiring to the dock.


My father cut the Romex with a lawn mower, and he wasn't wearing his glasses when he spliced the wires back together. He put black to white and white to black--screwing up the polarity.


Polarity doesn't matter when you're just running light bulbs. But it really matters when you're running a 3/4 hp electric motor.


My father dove off the dock, and the juice in the water hit him. He couldn't yell for help, as his vocal cords were paralyzed. Somehow he got the strength to get out of the water. In retrospect, he'd been noticing a bunch of dead fish floating on the water surface all week.


A year or two later, he did the same thing--spliced wires wrong. When I came into the boathouse with my pontoon in the dark, I could see sparks flying when I touched the cables.


Wiring is important, and it's even best if all wiring going to a dock is kept in conduit. And the circuit should be shut off anytime nobody's using the dock and lift.
 
I would strongly suggest turning off batteries at end of each day no matter what body of water you're in. ⚓️
 
We are in salt water here, and the boat is kept in a wet slip in the marina, so it's always in the water.  Salt water by itself will cause electrolysis, which will eat the softest metal it can find.  Add any stray currents to the mix and you've got the makings for some real problems if you don't pay attention.


I inspect my zincs every time I go out in the boat.  There are 3 locations on my boat: at the rear of the port pontoon, at the rear of the starboard pontoon, and underneath the engine bracket.  The zincs consist of a set of two discs about 2.5" in diameter that are held together by a threaded bolt.  They fit into a mounting bracket that has a hole drilled in it; one disc goes on the top of the bracket, the other goes on the bottom of the bracket, and they get tightly screwed together to the metal bracket.  It is imperative that no bottom paint is applied to either the zincs or the mounting brackets where they attach.  You want to make sure that you have a good metal-to-metal contact so that the zincs will "sacrifice" themselves.  I pick them up at West Marine and if I remember a set cost about $13 or so.  I swap them out about every 8 months or so.
 
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I have a 2015 bennington SL20. Pulled it for the winter today and tubes are pitted and appears to be hundreds of small holes. Did some checking and found this article on copper sulfate (http://www.lakegastongazette-observer.com/news/article_f22d4117-8ede-53e4-9ade-95f62d80e800.html) It seems that that chemical will pit pontoons. I checked and we have weeds treated and I think they may be using copper sulfate in weed treatments in my channel. If it is just attacking newer boats and not older ones, it is probably not electrical problems and sac. anodes probably won't help. It seems that Manufacturers have changed to a different alloy that may be reacting to this chemical.
 
Great Info !
Lived for 20 years in coastal Alaska berthing with a large amount of commercial fishing boats and stray current is a Big Deal..
Again, very knowledgeable information on this topic..
Thanks..
 
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