 |
|
26-12-2018, 16:29
|
#1
|
Marine Service Provider
Join Date: Dec 2018
Location: Adelaide, South Australia
Boat: Beneteau Oceanis 5.1
Posts: 24
|
Marine corrosion CAUSE elimination
Smile - I have the solution to the vast majority of CAUSES of corrosion.
Stray current causes electrolysis corrosion. Stray current can only be created by battery current, direct current (DC). So flows in the same direction 24/7. Usually from battery negative to Earth. Search for Wikipedia electrolysis. Note the apparatus power supply is red and black so DC. Not the shore power which is alternating current (AC). AC reverses direction every 1/2 Cycle or Hertz. So IF it takes off a particle in the first 1/2 Hertz it will replace it in second 1/2 Hertz.
So the only CAUSE is DC. The only two paths to the Earth are via water or air. Air creates a low current path so let us eliminate the vast majority stray current to the Earth via water.
Note that I am using the term current. That stray current is the CAUSE so to eliminate it we must measure current. Not voltage. Do a Google search for marine electrolysis and click on sea bis. There is no commitment or fee for advice. Spend a little time and study. The knowledge gained with eliminate the CAUSE for 20 years.
|
|
|
26-12-2018, 19:20
|
#2
|
Moderator and Certifiable Refitter
Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 21,827
|
Re: Marine corrosion CAUSE elimination
No disrespect for your above analysis however there are some discrepancies in your opening post.
1. quote Stray current can only be created by battery current, direct current (DC).
This suggests all stray currents are created by the ship's battery. Clearly not true, stray currents were a problem well before vessels were fitted DC batteries. Think bronze skin fitting on wooden hulls with no battery aboard etc.
2. quote Note that I am using the term current. That stray current is the CAUSE so to eliminate it we must measure current. Not voltage.
I agree measuring the current is a good starting point however eliminating voltage will eliminate the current. Current only flows if there is a voltage present but as the opposite is not true, eliminating current is a good starting point.
Again, no disrespect to your analysis.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
|
|
|
26-12-2018, 21:14
|
#3
|
Registered User
Join Date: May 2011
Location: San Diego CA
Boat: Liberty 458
Posts: 2,207
|
Re: Marine corrosion CAUSE elimination
Seriously? Perhaps you could read some more Wikipedia articles.
Might I suggest you read some articles on dissimilar metals, the chemistry of water and seawater and cathodic protection. You might also include something on ship electrical systems and grounding.
Sure current is important but have you conducted a corrosion survey just measuring current. There is a good reason why voltage is a potential difference.
|
|
|
27-12-2018, 00:14
|
#4
|
Registered User
Join Date: May 2010
Location: Sydney Australia
Boat: Fisher pilothouse sloop 32'
Posts: 3,497
|
Re: Marine corrosion CAUSE elimination
Have you just completed an online corrosion engineering course?
__________________
Rob aka Uncle Bob Sydney Australia.
Life is 10% the cards you are dealt, 90% how you play em
|
|
|
27-12-2018, 03:46
|
#5
|
Senior Cruiser

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 52,446
|
Re: Marine corrosion CAUSE elimination
Greetings and welcome aboard the CF, Corrosion-Eng.
Is "sea bis" your business? If so, you might be interested in our "Vendors" membership.
➥ http://www.cruisersforum.com/forums/vendor/register/
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
|
|
|
27-12-2018, 03:52
|
#6
|
CLOD
Join Date: Jul 2007
Location: dirt dweller in Jacksonville Fl
Boat: none
Posts: 20,902
|
Re: Marine corrosion CAUSE elimination
Self promotion thread not going well
__________________
Don't ask a bunch of unknown forum people if it is OK to do something on YOUR boat. It is your boat, do what you want!
|
|
|
27-12-2018, 05:25
|
#7
|
Registered User
Join Date: Apr 2015
Location: Stockholm, Sweden
Boat: Sun Odyssey 45.2
Posts: 165
|
Re: Marine corrosion CAUSE elimination
"This suggests all stray currents are created by the ship's battery. Clearly not true, stray currents were a problem well before vessels were fitted DC batteries. Think bronze skin fitting on wooden hulls with no battery aboard etc".
What happens between bronze and wood?
|
|
|
27-12-2018, 10:45
|
#8
|
Registered User
Join Date: Jan 2012
Location: Novato, California
Boat: Rafiki 37
Posts: 288
|
Re: Marine corrosion CAUSE elimination
|
|
|
27-12-2018, 12:42
|
#9
|
֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,137
|
Re: Marine corrosion CAUSE elimination
So the OP essentially has the cure for cancer but isn't willing to share it.
In some places, some folks would just say "Let's attach some battery jumpers to the guy and see if we can teach him to share nicely."
Of course, no one in this forum would say that. Still, it's a thought. Let's assume he really DOES have the cure, and he's just being greedy.
|
|
|
27-12-2018, 12:48
|
#10
|
Registered User
Join Date: Sep 2014
Location: Fiji Airways/ Lake Ontario
Boat: Legend 37.5, 1968 Alcort Sunfish, Avon 310
Posts: 2,750
|
Re: Marine corrosion CAUSE elimination
So if I screw a stainless plate to aluminum and leave it near the beach on Raro then I can come back in 20 years and there will be no corrosion?
|
|
|
27-12-2018, 14:50
|
#11
|
Marine Service Provider
Join Date: Dec 2018
Location: Adelaide, South Australia
Boat: Beneteau Oceanis 5.1
Posts: 24
|
Re: Marine corrosion CAUSE elimination
Hi All,
Thanks for your responses. T. E. Lawrence stated correctly.
From my experience based on 2 marine electrolysis degrees, 10 years research and development in 223 vessels, with 16 years commercial with 8 year money back guarantee, measuring current flow to the Earth and reducing that below the level that can create corrosion, is 100% successful. However I missed the ABYC change in terminology and will address that.
We use a microprocessor with 20 year design life,, sensitive to 10 millionths of an amp. We measure current in parallel so we cannot distort actual current.
Galvanic corrosion is less that 1/1,000 that of electrolysis. A one Kg (2 pounds) anode generates one millionth amp protective current. Electrolysis (stray current generated corrosion) starts at 100 micro amps. I have measured 9 amps. When stray current is eliminated then galvanic is easily reduced or eliminated by anodes.
Corrosion-Eng
|
|
|
27-12-2018, 16:14
|
#12
|
Registered User
Join Date: Aug 2003
Boat: Dragonfly 1000 trimaran
Posts: 7,295
|
Re: Marine corrosion CAUSE elimination
Breaking out the popcorn...
__________________
'You only live once, but if you do it right, once is enough.
Mae West
|
|
|
27-12-2018, 16:33
|
#13
|
Registered User
Join Date: Feb 2016
Location: Canada
Boat: T37
Posts: 2,338
|
Re: Marine corrosion CAUSE elimination
|
|
|
27-12-2018, 16:46
|
#14
|
Registered User
Join Date: Dec 2009
Boat: JBW club 420, MFG Bandit, Snark
Posts: 874
|
Re: Marine corrosion CAUSE elimination
Quote:
Originally Posted by hellosailor
So the OP essentially has the cure for cancer but isn't willing to share it.
In some places, some folks would just say "Let's attach some battery jumpers to the guy and see if we can teach him to share nicely."
Of course, no one in this forum would say that. Still, it's a thought. Let's assume he really DOES have the cure, and he's just being greedy.
|
He's selling a thingy with lights that light up and tell you that you have "current" and when those lights come on you switch off circuits until the lights return to normal and you have thereby diagnosed the circuit on your boat causing current. You still have to cure the problem, somehow. I think that's what is going on.
Savvy?
__________________
I love big boats and I can not lie.
|
|
|
27-12-2018, 16:48
|
#15
|
Moderator

Join Date: Feb 2011
Location: SF Bay Area
Boat: Islander 34
Posts: 5,480
|
Re: Marine corrosion CAUSE elimination
Interesting, though measuring stray currents does not a thing to eliminate stray currents. Stray currents can be DC or AC (ac ground loop) when at a dock or DC only away from the dock. So right there I find the original OP's posting to be slightly, hum inaccurate or at least unclear.
More then likely the OP is selling an impressed current protection system, which is DC.
Adding a simple impressed current system with a silver reference, DC + plate and micro-ampmeter is fairly simply done. Though many a company charge an arm and a leg for their black box voodoo, it's actually the simplest thing to make.
Of course adding a galvanic isolator on the AC mains can help in many cases, but not all.
OP may wish to post to the Commercial section...
|
|
|
 |
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|