The official "Stray Current II" thread. '07 260DA

[Stray Current]

i just bought a 260 seems one porthole leaks .do they just unscrew and come out ?

Yes the screws on the inside go through the trim ring on the inside into the body of the porthole and it's sandwiches the hull.

Before I went through all the trouble of pulling it out I would check to make sure the latches are tight and the little dogs at the end of them are screwed in to put the most pressure against the plastic. I also took a little Hayward pool filter o-ring lubricant to the gasket around the plastic to seal that up. They could be a little dry by now

 

[Stray Current]

Bilge so clean and dry

Out and about at the Westin in Cape Coral

 

[Stray Current]

The calm before all hell broke loose last weekend! Had to hide amongst the much taller sailboats in an anchorage with my antennas down for the night!

 

[Stray Current]

I have had a genuine oe dometic rebuild kit for this vacuum pump on my shelf since the first winter I bought this boat in 2019.

I have no idea why the hell I waited for the hottest week so far in 2022 down here by the surface of the sun in Florida to let it fail...

I'm out for maintenance once more! Going to touch up the water line and the outdrive, change the zincs, plugs, cap and rotor for the distributor, and the wires.

Despite all the "totally transitory" inflation that has nothing to do with an agenda we've been getting pretty good use out of the boat.

I'm struggling though. I'm not using it anywhere near what I used to in NJ. Just too damn much trouble to get to it with it so far away.

I feel like I'm creeping up on a very hard decision that's going to find someone in an incredibly well-kept boat for far less than it cost to have it that way

 

[Stray Current]

Bravo III corrosion control: copied and pasted from something I wrote elsewhere

I have a 2007 SeaRay 260 Sundancer with a 6.2 MX MPI horizon with a Bravo III outdrive. In December 2019 I had the transom assembly replaced with an OEM Mercruiser SeaCore unit. The drive is the original 2007 and has been equipped with a stainless steel Simrek shower since the transom assembly was replaced(when I purchased the boat) there is an appropriate gap between the micron csc bottom paint and the drive.

I’m using quicksilver or martyr aluminum anode sets, and I was in brackish water in Barnegat bay New Jersey for the 2020 season, and I’ve been in the Caloosahatchee river in southwest Florida since 7/2021.

I didn’t notice as much corrosion in nj, but I was only in from 5/20 to 12/20. Now that I’m in Florida I’ve had to sand, acid wash, prime and paint the drive 3 times from 7/21 to 7/22. This represents about 4 months not in the water.
Despite proper prep the paint blisters off and I can’t figure out why. Primocon/trilux

I’ve tested the potential with the quicksilver reference electrode several times and I always find it to be within the acceptable range for brackish/salt water. I replace the anodes every 2-3 months when they look like they need it.

The mercathode system is a blue controller using the transom assembly mounted electrode. The electrode was part of the new transom assembly and has been kept clean. It has never been contaminated with paint. The mercathode test procedure indicates that it is working and the current is within acceptable range for the water type/drive/prop material. The props and drive shower are also primed and painted with trilux

The bonding system on the entire boat tests properly. The mercruiser bonding straps are also intact with less than 1 ohm from any one component to another. The galvanic isolator is working and a fluke in-line milliamp meter on the shore power ground indicates that I am NOT being affected by stray currents returning over my shore power ground conductor, despite the name

My question is, what are my next steps? It’s clearly electrolytic action causing the coating failure.

Should I purchase a red controller?
Do I need the red controller with hull mounted electrodes?
Should I switch to magnesium and replace monthly?
Do I need a 17 pound magnesium block at the dock, tied via quick connect to the bonding system?
Is bourbon the answer?

I’ve done my due diligence, but I definitely need a little help now.

Last picture with no gap in bottom paint actually has 3/4” gap from micron csc to the drive, but hit with trilux. 2 weeks ago. I had oysters growing in the gap last time.


Since typing this originally I’ve ordered a red mercathode controller with 2 additional anodes. Going to start with the controller and add the additional anodes on next haul (if needed)

I’ve also decide to bond my starboard transom eye to the vessel bonding system. This will allow a hanging anode to be clipped on there with an alligator clip. Going to start with a 3 pound aluminum unit. I suppose I could use a 17 pound magnesium unit we bury with propane tanks if needed

Kentucky bourbon isn’t a solution, but it helps…

what’s next?

@Lazy Daze ?

 

[DWABoat]

Sounds like you are very educated on this issue. I have the same hanging anode setup on my 280 with twins and finally got my voltage in the right range because I am running a passive system of only anodes. Seems like your impressed current system isn’t doing what it should.

For my work boat, an aluminum hull 45 footer in freshwater, we ended up getting an impressed current system from ElectroGuard https://www.boatcorrosion.com/

I had to work with them on the phone numerous times while they finally got the footprint of the system correct. The engineer working with us was very helpful.

You may have to consider abandoning the Merc system and going to a custom setup.

 

[Stray Current]

If I decide to keep the boat I may definitely look into that. I’m still struggling with that decision.

As far as the knowledge, I did some reading and research. Since this page seems to get a lot of traffic and I get a few PMs with questions about what I’ve done, here are the resources:

Mercruser SB2013-02- corrosion prevention and maintenance https://holesbaymarine.co.uk/catalo...BVQQSRI5JE6RCFJVBFER2OJ5CUWVCTG5DUCWSBFZYGIZQ


Crowley yacht yard tip #11- shorepower http://crowleysyachtyard.blogspot.com/2009/02/crowleys-tip-11-when-your-vessel-is.html

Boatingmag galvanic isolator test - illustrated
https://www.boatingmag.com/testing-galvanic-isolator/

mercstuff mercathode testing
http://www.mercstuff.com/mercathodetest.htm
Mercathode kit red w/ 2 transom anodes
https://www.partsvu.com/mercathode-kit-42600a14.html

Mercathode reference electrode, but holy hell I paid les than $80 shipped 12/2021 !
https://www.partsvu.com/tester-electrode-91-8m0135998.html

boat zincs hanging anode
https://www.boatzincs.com/hanging_anode_aluminum.html

And of course, the workhorse in my stable - Fluke 117 DVOM (the 87,376,and 1507 rarely come out to play
https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-117

 

[DWABoat]

If I decide to keep the boat I may definitely look into that. I’m still struggling with that decision.

As far as the knowledge, I did some reading and research. Since this page seems to get a lot of traffic and I get a few PMs with questions about what I’ve done, here are the resources:

Mercruser SB2013-02- corrosion prevention and maintenance https://holesbaymarine.co.uk/catalo...BVQQSRI5JE6RCFJVBFER2OJ5CUWVCTG5DUCWSBFZYGIZQ


Crowley yacht yard tip #11- shorepower http://crowleysyachtyard.blogspot.com/2009/02/crowleys-tip-11-when-your-vessel-is.html

Boatingmag galvanic isolator test - illustrated
https://www.boatingmag.com/testing-galvanic-isolator/

mercstuff mercathode testing
http://www.mercstuff.com/mercathodetest.htm
Mercathode kit red w/ 2 transom anodes
https://www.partsvu.com/mercathode-kit-42600a14.html

Mercathode reference electrode, but holy hell I paid les than $80 shipped 12/2021 !
https://www.partsvu.com/tester-electrode-91-8m0135998.html

View attachment 131021

boat zincs hanging anode
https://www.boatzincs.com/hanging_anode_aluminum.html

And of course, the workhorse in my stable - Fluke 117 DVOM (the 87,376,and 1507 rarely come out to play
https://www.fluke.com/en-us/product/electrical-testing/digital-multimeters/fluke-117

marine corrosion is certainly a fascinating science. I have the exact same test kit. The engineer consulting with us on our fire boat told me corrosion can definitely be defeated, if the system is properly configured. He was right with our boat. You know more than I do about this topic, so I have no words of wisdom other than to keep working on it.

 

[ttmott]

The corrosion issue may not be your boat. My boat was being eaten up by the boat in the next slip to me.
Have the water checked around your slip.
In my case we had the marina's management side by side during testing of the water around the slip and found the garbage scow next to me was leaking badly and as a bonus found an electrical issue with the dock power. They had that boat out of the marina in a couple of days. I guess they have been having issues with those owners and this was the straw that broke the camel's back.

 

[Stray Current]

The corrosion issue may not be your boat. My boat was being eaten up by the boat in the next slip to me.
Have the water checked around your slip.
In my case we had the marina's management side by side during testing of the water around the slip and found the garbage scow next to me was leaking badly and as a bonus found an electrical issue with the dock power. They had that boat out of the marina in a couple of days. I guess they have been having issues with those owners and this was the straw that broke the camel's back.

I’m actually renting a slip at a private home, and there aren’t any boats for at leas 150’ in any direction which helps, and they’re lift kept. Between the isolator and the milliamp meter in line of the ground at my shore power outlet I’m not showing any current on my ground path. Other than that, I’m not sure how I would test that.

That fact that I’m on a GFCI would suggest I’m not the one emitting stray currents to the water

 

[ttmott]

I’m actually renting a slip at a private home, and there aren’t any boats for at leas 150’ in any direction which helps, and they’re lift kept. Between the isolator and the milliamp meter in line of the ground at my shore power outlet I’m not showing any current on my ground path. Other than that, I’m not sure how I would test that.

That fact that I’m on a GFCI would suggest I’m not the one emitting stray currents to the water

The GFCI trip point is much greater than damaging galvanic corrosion current. Something is pulling the ions from the aluminum. It seems you have gone over the AC power system and found it healthy including the galvanic isolator and the bonding network. The thing you should see also is significant erosion on the boat's zinc anodes as if the aluminum on the drives is eroding and the boat's bonding system is healthy. If you are seeing erosion on the drives but none on the zinc anodes is indicative of issues on the boat.
There could be other current in the water like from the home's electrical system. At this point I'd still verify the water with a Silver/Silver Chloride reference cell like they did at my marina. Here is some info that may help -
https://stevedmarineconsulting.com/...rosion-protection-level-editorial-old-vs-new/

 

[Stray Current]

I’ll look into the cell to test that. Believe it or not I’m not seeing any real corrosion of the aluminum. Just the paint failure and rapid deterioration of the anodes. They get a yellowish coating rather quickly and erode

this was hung roughly 24 hours ago.

 

[Stray Current]

I did some more testing and found that I had a high resistance from the transom assembly to the engine block. It was about 25 ohms, so I installed a jumper from the assembly bolt to the bell housing bolts and now I read 2.7 ohms from the steering arm to the exhaust elbow bolt. Much better!

After a week it seems the zincs aren’t getting as torn up and developing as much of the coating. I think perhaps the difference in potential between the transom assembly and the other bonded underwater metals was exacerbated by the higher resistance.

I’m still using the blue mercathode controller as the red one was defective. I’m waiting for a replacement and I will test that once installed.


At this point it’s looking like the boat may be getting sold. Despite being in Florida I just don’t use it enough, I’ve put less hours on it in the last year than a typical July and August up north. I had big hopes of buying a waterfront home but I got hung out on some money and that’s not a possibility anymore with the prices and rates. With it sitting in a slip away from the house it just makes everything a project to do anything with it. It’s become more of an obligation than a joy.

I think the cash from selling and the 2500-3500 a month in slip, fuel, upkeep and insurance may be better invested. Maybe revisit the whole concept again at some point in the future, but probably not

 

[Stray Current]

Well, it’s been an interesting few weeks down here in southwest Florida. The generator business is on fire!

Some major damage all around but fortunately the house is ok. Lost a few shingles, a new fence, and got some new scratches and scuffs on the truck and boat to have fixed. Overall very fortunate compared to many.

I figured since we have some time for new charts, channel markers, and debris removal now was a great time to blast an outdrive. It’s honestly not quite as bad as I expected, but I didn’t want him to get too aggressive on the pitting with the glass bead.

Now to research the best chemical prep and coating processes

 

[techmitch]

Zinc chromate primer is your friend. Some recommend using very shortly after the strip.

 

[Nater Potater]

Zinc chromate primer is your friend. Some recommend using very shortly after the strip.

Aluminum will "grow" a native oxide layer in a few short hours which effectively blocks the paint from getting a good grip, so it needs to be coated pretty quickly after the strip. Check out the attached Mercruiser manual #14, page 1A-7 for Merc's take on metal prep for outdrives. I cheapened-out and used a dilute HF-based aluminum cleaner/etchant I have access to (it's used for cleaning aluminum semi trailers), then hit it with zinc phosphate. I'd rather used zinc chromate, but it's supposed to work with aluminum just as well. Time will tell, but it's working fine so far. You can check out my build thread for the troubles I went through with heavily pitted outdrives if you're interested.

 

[Stray Current]

Bead blast, round one

Bead blast, round 2 2 months later. I told him just send it and dig all the oxide out. Luckily it didn’t result in any oil spots on the deeper pits.

2 coats Pettit alumaprotect applied.

1 coat Pettit epoxy, filler, and a second coat of Pettit epoxy primer next

 

[ttmott]

View attachment 139269 View attachment 139270 View attachment 139271 View attachment 139272Bead blast, round one View attachment 139273
Bead blast, round 2 2 months later. I told him just send it and dig all the oxide out. Luckily it didn’t result in any oil spots on the deeper pits.View attachment 139274
2 coats Pettit alumaprotect applied.

1 coat Pettit epoxy, filler, and a second coat of Pettit epoxy primer next

Nice Job!

 

[Stray Current]

“Spring” detailing complete!

Next up:
finish outdrive fill/paint
remount drive
new blower
trim sensor
anodes
touch up bottom paint
Hill marine 4x4 props 18 pitch
plugs, cap, rotor
belt

still waiting on canvas and vinyl estimates

 

[Stray Current]

I have come to a few conclusions:

This paint all sucks when brushed. I figured it will be gloppy no matter what so I decided not to bother with filler. It’s a 16 year old saltwater bravo 3. Send it!

I’ll be adding another coat of vivid yellow followed by 2 coats of black trilux once it’s hung on the boat.

My main concern is corrosion control. I’ll hide it underwater for long periods so aesthetically it doesn’t matter. If this doesn’t correct my galvanic reaction Neptune can have it