Zincs

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I/O and saildrive corrosion in the Great Lakes is now and has always been a significant problem and every claim I have investigated has been at least in part been due to lack of proper anodes.[/QUOTE]

Hi Boat Poker, Don't know anything about sail drives but a few of my boats had outdrives and like the outboards, they all came from the factory with anodes so theoretically they should not be a problem compared to a completely unprotected boat with inboards. Iv'e done more damage to my outdrives cleaning them with acid products trying to get the damn zebra mussels off but like I said, I have never had any serious corrosion issues. Maybe the anodes themselves are the problem in fresh water :)

You should look into the acids that are used to clean the hulls these days, I have long suspected these are doing damage to both the fiberglass and the metals, especially outboards & outdrives.

Spent most of my time on Huron, GBay, Erie, Superior. I don't doubt your right however, that the lakes are changing. I'm guessing they are far more acidic in places due to acid rain. Ironically, this is a subject we don't hear much about these days. Perhaps has taken a back seat due to more fashionable issues like global warming.

Your likely to get mixed reactions from a lot of Great Lakes boaters attending your anode seminar but I'm sure you will have the ear of everyone present when it comes to electrocution issues. Wouldn't mind attending that myself, can't count how many times I've dropped the power cord in the water.
 
I'd venture a guess that the conductivity of Erie and Ontario is many times that of Superior due to higher TDS and mean temperature.
 
I too clean the oxide off of my zincs with a nonferrous brush.

I've thought of switching to an aluminum alloy anode, but haven't as yet.
 
Capt Kangeroo said:
"...Great Lakes boaters attending your ... seminar ... [you]will have the ear of everyone present when it comes to electrocution issues. Wouldn't mind attending that myself, can't count how many times I've dropped the power cord in the water.
Click to expand...

I somewhat paraphrased CK's quote. But, feel it still rings true on question I have for boatpoaker.

If live power line is in water... is fresh or salt water more likely to shock person in water?

Thanks, Art
 
go see electric shock drowning .org lots of info. Very very scary stuff.
salt water conducts rather well. Fresh water less so. When you are in the water your body is a better conductor than fresh water. You don't even have to touch anything. Just swim into the wrong place.
 
ps and bf - Thanks, Art
 
Psneeld and BryanF have it right. While Kevin Ritz discovered "electric shock drowning" through investigating his sons death (and proving the coroner wrong) Kevin frequently works with David Rifkin who has probably the best description of the issue on his website.
Kevin and David (ret'd nuc commander) worked together on the definitive study on the issue funded by the USCG.

I hosted David and his Marine Electrical Safety seminar at the Royal Hamilton Yacht Club last year and it is the best money I have ever spent on a course. Read ever single page on his site .... it is a gold mine.

I am required to attain a number continuing ed credits each year to maintain my AMS status and try to organize as many courses as I can in Ontario because its too damn expensive to fly to Lauderdale, Annapolis or Seattle.
 
Art said:
If live power line is in water... is fresh or salt water more likely to shock person in water?
Click to expand...

Unless the insulation is damaged, dropping the cord in the water doesn't harm anyone unless it's unplugged from the boat, live, and the end is dropped in the water.

The recommended procedure though is to turn off the dock breaker, connect the power cord, and only then turn the dock breaker on. A cord that's dropped in the water with the power off is not a hazard.

This also prevents arcing and damaging your power cord and shore power inlet's connections if the boat is attempting to draw power.
 
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All I previously worried about around docks, regarding stray electric current allowed into water, was for protection of underwater metal parts (and their connected-to inside boat metal parts - can we spell anodes, ya know - Zincs, from whence this thread began) Guess that's basically because I never swim at docks... only while on the hook. Regarding my boat's electric connection I never leave it plugged in while away and am careful to make sure all portions are in good shape and securely fastened away from water contact.

That said... TLC Video-Lucas's Story video on www.electricshockdrowning.org BryanF provided did wake me up! I have seen kids in waters around docks. And, anyone could fall in.

I will be even more vigilant to keep my eyes open for potentials of stray currents into water. Luckily the covered berth area we dock has relatively few slips and it seems boat owners there are careful. But... cha never know... I'll be inspecting more carefully anywhere near my berth from now on!

IMO - This water borne electrocution discussion and learning opportunities are thoughtful and needed diversion/hijack from original "Zinc" thread.
 
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Well to try and tie the drift to the original thread. Before you dive overboard in fresh water to check your zincs that do not work in fresh water be sure to check out the electrical safety of your surroundings.
And I can tell you that the zinc anodes on Florence A are as white as white can be as the boat was stored in fresh water. And I can tell you that I have had all the bottom coatings off back to bare steel because the paint was bubbling off the steel from electrolysis. Now, fortunately the damage was repairable. BUT I don't think that there will be zinc anodes on my boat when I plan to sit in fresh water for the bulk of the time.
 
BryanF said:
Well to try and tie the drift to the original thread. Before you dive overboard in fresh water to check your zincs that do not work in fresh water be sure to check out the electrical safety of your surroundings.
And I can tell you that the zinc anodes on Florence A are as white as white can be as the boat was stored in fresh water. And I can tell you that I have had all the bottom coatings off back to bare steel because the paint was bubbling off the steel from electrolysis. Now, fortunately the damage was repairable. BUT I don't think that there will be zinc anodes on my boat when I plan to sit in fresh water for the bulk of the time.
Click to expand...

Hi Bryan

Zinc can only do OK anode-work in fresh water as long as their surfaces are consistently scraped/scrubbed completely clean with rigid metal scraper and stiff wire brush … like… at least every couple/few months or more often. I figure your “white” colored zincs were not regularly tended to in this way???

Magnesium removes need to keep anode surfaces clean in fresh water. It also is more costly, disappears by shedding-off much more quickly than zinc, and therefore more often needs work performed to replace the several old/then-useless Mag pieces.

I love to go under our Tolly while at anchor (never at dock or with gen set running) for tending to anode surfaces as well as check everything under boat carefully with flood light, knife, etc... during each anchor-out. Helps keep me young and healthy!

Happy Anode Daze! - Art :socool:
 
Art said:
...disappears by shedding-off much more quickly than zinc...
Click to expand...


An easy sign to tell if your "sacrificial anode" is doing its job is when it sheds off quickly.

ImageUploadedByTrawler Forum1415636375.047596.jpg

The science behind the recommendations is not that difficult to comprehend. The sacrificial anodes are not very expensive when compared to brand new props, shafts and such.

Honestly, why settle for duct tape that may work out ok when condoms are proven effective and readily available? Replacement cost is a pretty silly argument.
 
The "problem" I have is the variation between seasons. During the summer in the harbour the water conductivity, salinity and temperature is high. During the winter the temperatures drop, and fresh water from the frequent rains are on the surface so conductivity plummets.

Boat use is more frequent in the summer , less in the winter.

So my current solution is to scrape the passivating oxide off in the winter.

A better solution is to find an aluminum alloy anode that will fit my hull anode on the stern, near the surface.

Interestingly enough, the prop and rudder zincs works fine and just requires replacement. No oxide buildup. I rationalize this due to depth (more saline in the winter) and turbulence. Shrug.

But I don't want to mix anodes, so I stick with zinc alloys, or else I'm changing the rudder and prop anodes more frequently.

This would cause me to litter the ocean floor with 1/4" Allen wrenches.
 
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CPseudonym said:
An easy sign to tell if your "sacrificial anode" is doing its job is when it sheds off quickly.

View attachment 34306

The science behind the recommendations is not that difficult to comprehend. The sacrificial anodes are not very expensive when compared to brand new props, shafts and such.

Honestly, why settle for duct tape that may work out ok when condoms are proven effective and readily available? Replacement cost is a pretty silly argument.
Click to expand...

Yo, Craig... I'm not arguing at all and I know full well Magnesium works without tending to it in fresh water. And, that Mag's replacement cost is not even a real consideration... in the long run. What I am saying is that Zinc works in fresh water too as long as its surface is kept scrapped/scrubbed clean, such as I enjoy often doing to mine. The peripheries I mention such as cost and replacement schedules are pretty much meaningless... but they are fact!

For more pro-zinc items, read this thread’s post numbers: 4, 5, 7, 9, 10, 12, 13, 23, 31, 33, and… 44 for good chuckle!

Then you can read several other posts with diametrically different opinion!

YRMV!! :dance:
 
BryanF said:
Well to try and tie the drift to the original thread. Before you dive overboard in fresh water to check your zincs that do not work in fresh water be sure to check out the electrical safety of your surroundings.
On the ESD issue. My wife and I witnessed one in Traverse City MI in August 2011. It only takes milliamps to completely paralyze you in fresh water. The dock electrical system was leaking the electricity into the water in this case. Two teens jumped off the dock to cool off and one did not come up. Tragic.
We tell everyone we see swimming in fresh water marinas of the dangers and I have posted on other forums as well.
DO NOT SWIM IN FRESH WATER MARINAS!!! PLEASE!!!!
It was unbelievable how quickly this happened....I will never forget the screams of the friends of this unfortunate youth.....
Click to expand...
 
One way to determine if your boat has the correct anode and is functioning as designed for your waters, is to use a silver/silver-chloride electrode with a DVM. It will tell you if you have enough or to little anode, is your bonding system working or is there stray electrical currents in the marina from a neighbors boat or from the marina, if you have a galvanic isolator or not, plugged into shore power or not can also change the requirements. You can buy a reference probe for less that $150 or hire an ABYC tech.

Depending on what source you read, Al can work in fresh, salt or brackish but without testing, which source are you going to follow?
 
I guess that what I was trying to say. The electrolyte can be dynamic in cathodic protection using an anode. One size rarely fits all, and just because it works for your boat, doesn't mean it is going to work for others.

Sometimes we forget that around here...

PS: I'm sure someone will come up with a set and forget impressed current protection including "change anode" alarms for recreational boats soon enough, if it doesn't already exist.
 
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