Impressed current systems are a waste of money.

Submitted: Monday, Feb 02, 2015 at 15:05
ThreadID: 110955 Views:2569 Replies:3 FollowUps:14
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For what its worth I was reading another post and wanted to reply but it appears to be closed so Ill just reply here.
I have one on the 2nd and vehicle I purchased and have disconnected it as all it does is flatten the battery when im away. It draws .05 of an amp!!

I work offshore on oil and gas platforms where impressed current systems are seen. Im a CSWIP qualified 3.2U if you want to know my quals.

Now impressed current cathodic protection systems do work, the steel just has to be immersed in an electrolyte. On a platform very basic version is you have a generator running topside with the platform hooked up to the negative terminal and the impressed current anodes hooked up to the positive and the current flows though the salt water and protects the structure from corrosion.

here is the big simple point why thei wont work on your vehicle unless its submerged in water.
1. The anode is insulated from the structure.
2. This system does not work above the waterline, nor is it effective in the splash zone!! Why because the structure needs the electrolyte to work the current flows through the electrolyte. If it worked in the air it would be the corrosion protection system above the water line, but it isnt, its purely the paint coat that stops corrosion above the waterline and keeping in maintained.
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Reply By: pop2jocem - Monday, Feb 02, 2015 at 16:40

Monday, Feb 02, 2015 at 16:40
Well to me that explanation sounds a lot more believable than that a box of mumbo jumbo with no way to complete a circuit is doing anything other than transferring some dollars from one pocket to another.

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Follow Up By: 3.2U CORROSION SPECIALIST - Monday, Feb 02, 2015 at 17:19

Monday, Feb 02, 2015 at 17:19
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Follow Up By: Member - Phil 'n Jill (WA) - Monday, Feb 02, 2015 at 21:26

Monday, Feb 02, 2015 at 21:26
So effectively it is a transfer of currency - rather than current, Pop

Cheers all - Phil
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Follow Up By: pop2jocem - Monday, Feb 02, 2015 at 21:59

Monday, Feb 02, 2015 at 21:59
If you are talking about the system that Peter Brock and probably others were flogging yes, I do believe it is a load of snake oil.

The one that Corrosion Specialist explained I would have said is a much more professional and probably effective system.

I would however add, if anyone wants to lay out their hard earned on the one the snake oil salesman are pedaling....go for's your dough.

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Follow Up By: Dennis Ellery - Monday, Feb 02, 2015 at 23:19

Monday, Feb 02, 2015 at 23:19
The system that 3.2u described has been used extensively for years on wharf piling.
Witch doctors have been flogging this as being suitable for motor vehicles for years along with ultrasonic animal repellers and petrol pills etc.
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Follow Up By: Member - Scott M (NSW) - Tuesday, Feb 03, 2015 at 11:41

Tuesday, Feb 03, 2015 at 11:41
This reminds me of one of those mega-engineering shows on TV ... if my memory serves me correct, the Sydney Opera House has a significant array of sacrificial anodes built under it. If they weren't there the whole edifice would eventually corrode away and collapse.
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Reply By: Erad - Tuesday, Feb 03, 2015 at 09:16

Tuesday, Feb 03, 2015 at 09:16
3.2U's teatment of the corrosion problem is good. You do need an electrolyte for corrosion to occur. In most 4WD applications, the chassis and body are dry for most of the time - you don't have any electrolyte in the affected areas and you would not have any impressed current flowing. However, when the affected areas do get wet - with fresh water or salty - then corrosion can and does occur. For the rest of the time, no current would flow and no corrosion will occur either. Remember that with Oil Rigs, buried gas pipelines etc, they are exposed all the time, and also normally have a significant wall thickness of steel (including corrosion allowance). Motor vehicles have very thin sections, and are not normally designed with corrosion in mind. So therefore the systems may actually work in preventing corrosion.

Paint is still the best medium for corrosion prevention for cars, trucks etc, and the electro protections are merely a supplement. And no - I don't have an electric protection system on my vehicles, and I don't have the need for one either.
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Reply By: Sigmund - Tuesday, Feb 03, 2015 at 10:26

Tuesday, Feb 03, 2015 at 10:26
I've used this system to convert rust on old hand tools. It needs a solution of washing soda to work.
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Follow Up By: Member - Beatit (QLD) - Tuesday, Feb 03, 2015 at 12:25

Tuesday, Feb 03, 2015 at 12:25
G'day Sigmund,

Without letting the cat out of the bag what do you use as you power source and what do you use for a sacrificial anode?

Kind regards
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Follow Up By: Sigmund - Tuesday, Feb 03, 2015 at 12:34

Tuesday, Feb 03, 2015 at 12:34
A 12v battery charger Beatit. Just an old thing that was superseded by a smart charger. Anode: a scrap plate of mild steel.

It turns the rust dark grey. Ideal for items that are hard to treat with a wire brush, buffing wheel or the like. But if you want that bright steel look you're up for abrasion.
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Follow Up By: disco driver - Tuesday, Feb 03, 2015 at 12:45

Tuesday, Feb 03, 2015 at 12:45
On the subject of "restoring" old tools.

I'm told that the oldtimers (and some newcomers too) have used molasses with some success.

Apparently you immerse the rusty item in the molasses and leave it there for some considerable time.

I haven't tried it but would like to hear other opinions on how good it is, before I start on mine.

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Follow Up By: Sigmund - Tuesday, Feb 03, 2015 at 12:59

Tuesday, Feb 03, 2015 at 12:59
Yeah, molasses contains a mild acid, that's all.

Buy some rust converter you get a solution of phosphoric acid. Works in minutes with little mess. You can wipe it over with a wet rag and paint it.
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Follow Up By: Sigmund - Tuesday, Feb 03, 2015 at 13:10

Tuesday, Feb 03, 2015 at 13:10
I should add that the acids react with iron oxide to produce another compound that's grey and I think inert.
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Follow Up By: Dennis Ellery - Tuesday, Feb 03, 2015 at 17:29

Tuesday, Feb 03, 2015 at 17:29
HI Beatit
Modern battery chargers won’t work – use an old battery charger that puts out 3 amps.
If I didn’t have an old battery charger I would use a modern one with a battery in parallel.
You can alter the current flow by adjusting the depth of electrode in the electrolyte
Caustic Soda, as an electrolyte with 2.5 amps DC passed through it (negative to the part being cleaned) for about 24 hours will remove rust. It then becomes black oxide which can be removed with acid. I use a bare copper wire for the electrode. If you make the electrode copper (positive) it will lightly electroplate the steel with copper and you won't have any black oxide to clean off.
I mixed 30 grams of Caustic Soda to a litre of water to produce an SG 1050.
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Follow Up By: Dennis Ellery - Tuesday, Feb 03, 2015 at 17:36

Tuesday, Feb 03, 2015 at 17:36
Another method I have used is a solution of Hydrochloric Acid is also known as Spirits of salts or Muriatic Acid – available at Bunnings
In my experience it will strip heavy rust overnight when used in a 10% solution. Make sure you neutralise it before painting with a light caustic solution made of Baking Soda or Caustic Soda.

Not to confused with phosphoric acid – it won’t remove heavy rust – it converts only light rust to another compound that can be painted over.
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Follow Up By: Keith H7 - Tuesday, Feb 03, 2015 at 19:09

Tuesday, Feb 03, 2015 at 19:09
Try leaving rusty parts/tools in Coke a Cola will be surprised
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Follow Up By: Bob Y. - Qld - Tuesday, Feb 03, 2015 at 20:28

Tuesday, Feb 03, 2015 at 20:28

Had a lass working for us years ago, and her dad restored old engines. He immersed the parts in molasses, and as I recall, she said the bits came out as clean as. Definitely no rust left.

Don't forget it's heavy stuff. A 200L drum weighs about 340 kgs! Though you mightn't need that much, eh. :-)


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