How To Stop Metal Corrosion

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Copyright Property of Podean Electronic Industries Pty Ltd trading as SeaBis®.

•SeaBis Master is an industrial grade mini-computer with 20 years life. It is the simplest and most direct way to eliminate corrosion. You do not need a Blocker or impressed current when you use SeaBis Master System. SeaBis Master with How To Stop Metal Corrosion permanently eliminates the cause - stray current.

•Adding additional Anodes will only cost you more money than SeaBis.

•External references, proof we are correct, at the last page.


How To Stop Metal Corrosion in 3 Steps.

My background:

I am 72 and have been continuously fighting metal corrosion since I was 19.  I provide a publicly visible written 8 year money back guarantee:  "I will either eliminate the CAUSE of metal corrosion or pay you your money back.  With the provision How To Stop Metal Corrosion is fully complied with."  It has never been claimed.

I began by asking questions:

Why do metal fences corrode more at the bottom than the top:  The bottom is nearer the moisture of the Earth (the Earth we stand on. Not the mains power supply earth).

Why do radiators corrode before the engine body:  They are a lower electrical resistance than engine bodies / or most other harder metals so pass the majority of stray current that causes electrolysis. The metal corrosion we are only to familiar with.

Why do vehicles in damp areas corrode more than in dry areas.  The tires are rubber so a good insulator, unless they have damp walls.

Why are boats and yachts more prone to stray current causing electrolysis than vehicles.  They are sitting in a good conductor to the Earth.  Whereas vehicles are insulated from the Earth, providing their tires are dry 97% of the time.  For an explanation of 97% see and Questions or contact me:

Why do small to medium aircraft, as trucks, suffer from electrolysis when the large commercials do not.  The latter insulate battery negative from all metal.  There are exceptions:  Most aircraft have no method to measure stray current as it must be measured as current while fully powered up.  That leads me to SeaBis. 

That is exactly what SeaBis does:  measures current flowing to the Earth while your equipment is fully powered.  (The air around aircraft, in clouds, contains more than the tolerance level of 10% moisture - any metal in contact with the Earth, even remotely, passes stray current to the Earth so causing electrolysis.

Procedure to eliminate the CAUSE/S at the bottom of this page.


Metal Corrosion Explanation:

Metal corrosion is ongoing to ALL metal that makes contact with the Earth, by air, sea or land. This article examines the three-step process to stop metal corrosion: identify metal corrosion, understand the cause and eliminate the cause.  The same process applies to all metal in all environments. Air: moisture in clouds.

Metal corrosion may take any or multiples of several forms. Some typical examples are shown in Figure 1.

Electrolysis dissolves metal, 24 hours, every day. Some call this stray current "rust"

Step 1: identify the cause of metal corrosion: electrolysis
 • Propeller
 blades dissolve
 • Metal under the
paint  dissolves
 • Welds have a lower
resistance to current
so dissolve first
Propellor corroded Paint repair Welds dissolve before sheet metal
 • Plumbing  corrosion.
White growth is typical
 • Radiator core dissolves
so becomes porous
 • Patches of electrolysis is
caused by lower resistance
to current flow
Plumbing electrolysis Radiator leaks Patches of electrolysis



Step 2: understand the cause of metal corrosion-stray current

Stray current is dependant on an electro-chemical reaction.
Eliminate the stray current and you eliminate electrolysis:
  No SeaBis System     With SeaBis System  
Metal stray current causes corrosion Stray current Metal corrosion cause eliminated No stray current
  Stray current causing corrosion     No corrosion  




Understand Metal Corrosion

The Science behind metal Corrosion

Electrolysis, which continuously dissolves metal, every hour of every day is the cause of corrosion. Stray current causes electrolysis.   It is sometimes called "stray current rust." The corrosion occurs whenever damp to wet metal or a heating / cooling system or a metal connection to the earth that is not perfectly dry at least 97% of time. Batteries are the primary source of direct current  (DC), however mains power generated DC has the same effect.  Metal particles are dissolved by the DC electric current to the Earth via water, land or air, taking your metal with it.

All electronics must use DC.  They cannot operate without it. The battery’s DC - direct current - always flows in the same direction, carrying particles of your metal with it. In contrast, mains power is alternating current (AC) that reverses direction every half cycle (e.g., a 60 Hertz current reverses itself every 1/120 of a second) so dissolved particles are replaced every alternate half cycle. Therefore, alternating current cannot cause electrolysis corrosion.

The Causes of Metal Corrosion are:

Rust has very low corrosive ability compared to electrolysis. It requires a moisture content in the air of 10% or greater, to exist.  Even the Gobi desert exceeds that. Rust is easily prevented by paint or plating after all electrolysis CAUSES are eliminated.  Remember the bottom of fences corrodes first?  - It is nearer the moisture of the Earth.

Compared to electrolysis corrosion, galvanic corrosion also has low corrosive ability. Galvanic corrosion can be eliminated by anodes but only after electrolysis is eliminated. Sacrificial anodes can then work as designed.

Galvanic corrosion is caused by the natural voltage between two different metals in a conducting medium such as any type of moisture greater than 10%, even atmospheric moisture. The natural voltage never exceeds 1.2 volts and the current is in the millionths of an amp. A one-kilogram anode produces one-millionth of an amp of protective current. This can be demonstrated with two metal hulls, one inside the other and a sophisticated micro amp clamp meter or, much cheaper and more accurate by SeaBis Master.

Electrolysis varies from one thousandth of an amp to several amps  of current. I have measure 9 amps generated by a commercial VHF Transceiver power supply. To counteract this would require at least 1,000 kg (2,205 lbs) of anode to have any effect on the electrolysis, and probably 10,000 kg (22,050 lbs) to stop it completely, which is often more than displacement weight of the entire vessel / vehicle / installation. It is much better to eliminate the CAUSE than try to cure the effect. Having done so, then anodes can work as they are designed. Anodes are simply ineffective in the presence of electrolysis that is commonly at least ten thousand times stronger. It is best to eliminate the largest cause of corrosion first and then the remaining sources are easier to address.

Electrolysis is more aggressive than rust or galvanic corrosion by at least 10,000 to 1. It is generated by all electrics and electronics. They all require DC current.  A proportion of that current flows from the vessel / installation to the Earth. A ship causing electrolysis in a common conductor such as water will corrode other nearby ships. Electrolysis corrosion can only be measured as current, the cause identified and then eliminated.  Continuous monitoring of all DC sources (batteries) by SeaBis is essential to eliminate ALL causes, as they are often intermittent.


The Cause of Electrolysis

Reference Kelvin Absolute Law:

A battery’s negative terminal is actually at -12 volts and a battery’s positive terminal is at 0 volts. The Earth at  +1.2 volts.  Moisture at great than 10% is a very good conductor. Therefore, when there is a circuit from the negative to the metal of the installation / vehicle / aircraft / ship’s hull or engine, then negatively charged electrons are repelled from the metal to the earth, carrying your metal with it.  In science class, remember the two bar magnets, when placed with like poles adjacent so electrons adjacent, repelled each other?

All DC returns 80% or more of the current drawn from the battery’s positive terminal to the battery negative terminal. That is why the battery’s negative cable has the same copper diameter as the battery’s positive cable.

For example, a starter motor on a medium-size four-cylinder diesel drawing 180 amps will return 180 x 0.80 = 144 amps to the battery via the battery’s negative cable. If the metal is connected to the battery’s negative terminal then a proportion of the current will flow through the metal to the Earth, taking your metal with it.

On a fiberglass boat the same current flows through the propeller, the gearbox and then the engine’s cooling system. The accelerated flow rate in the cooling pump intensifies the electrolysis effect caused by the stray current.

The current flowing to the earth consists of negatively charged electrons. The Earth, at 1.1 to 1.2 positive volts, attracts some of that current. Only one-thousandths of an amp is sufficient to cause enough electrolysis that you can see visible corrosion in three months.  Accuracy requirement of 10 millionths of an amp with no disturbance of the circuit under measurement is met by SeaBis Master.

Note: Never try to measure this with a multimeter as the battery acid may explode. In addition, any reading, if you get one, must be inaccurate. The current must be measured with everything at full power and at an applied voltage (12 or 24 volts) without a current limit in the measuring device below 100 milli amps. The device must not have an effect on the circuit being measured.  Multimeters measure 1 volt at one-millionth of an amp and have an error probability of at least 1000:1. In addition they alter the circuit under test.



All metals have a natural voltage. That natural voltage is very low but always present. The natural voltage causes galvanic corrosion. When a copper wire connects two pieces of metal the copper wire transmits the current through itself rather than through the water, thus reducing the effects of galvanic current. However the battery’s positive or negative terminals must never be allowed to make contact with the bonding because electrolysis will increase dramatically causing large and extremely expensive corrosion of the installation's metal.


Step 3: Eliminate the Cause of Corrosion

Metal corrosion is caused by an electro-chemical reaction. When you eliminate the electric current then you eliminate the stray current that causes electrolysis.  We do so by making all metal electrically Open Circuit (disconnected) in full power use, from the World.  Then no current can flow either in or out so there can be no electrolysis, permanently. That is why our 8 year money back guarantee has never been claimed.

Please remember it takes 10 cumulative days of stray current  in one year to cause electrolysis you can see.  So SeaBis  must be permanently connected and How To Stop metal Corrosion complied with.  Then the cause/s of stray current are permanently eliminated.

Training at in Products at Training-eliminate the CAUSE corrosion-free

Excerpt from SeaBis Master Instructions at in Products at How To Stop Metal Corrosion Instructions.

To go to SeaBis: Do a Google search for SaBis System.


Procedure to Eliminate the Causes:

The causes are all electrically in parallel.  So the procedure is to disconnect circuits until you have a Normal on SeaBis Master.  Then (touch) connect each in turn, leaving disconnected any that cause electrolysis.  Those that are Normal - leave connected. On completion those causing electrolysis are disconnected so will have no power and are easily identified.  Now follow How To Stop Metal Corrosion to complete the diagnosis and repairs.

Products at: at Products



1: External reference: Proof we are correct, DC (batteries) cause metal corrosion: Wikipedia Electrolysis - the free encyclopedia

2: External reference: Proof we are correct, DC (batteries) cause metal corrosion: is-electrolysis-eating-your-boat.pdf

3: External reference: CorrosionPedia (Independent corrosion specialists) Article: how-to-stop-marine-corrosion-in-3-steps.htm

4: 8 year money back guarantee:  We will either eliminate the CAUSE of metal corrosion or pay you your money back.  With the provision How To Stop Metal Corrosion is complied with at at Products, 8 year money back guarantee. How To Stop Metal Corrosion must be complied with-see

5: Testimonials: at at Products, Testimonials with verification


Contact us:

If you want to comment or feel even slightly disappointed with our products we want you to contact us and we will rectify the matter: Email:

Glen Bishop of SeaBis
To go to SeaBis: Do a Google search for SeaBis System.
Address: 3 Arabian Court, Hindmarsh Valley, South Australia 5211.
Mobile / Cell Australia 61 (0)417 878 773, Office 61 (0)8552 6584, Skype: seabis1

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