Electronic rust protection (1 Viewer)

[banjorogers]

My Dad bought a 2001 Turbo Troopy that was an ex police vehicle from the Hervey Bay police force. Now we think it spent most of its prior life on Fraser Island, if you know of the place you would know the kind of treatment that it has probably seen. Dad, spending $45000 didn't want to have his new car rust away so when we first got it, we stripped the inside wall linings and floor linings out to have a look and give it a fish oil. But to our horror, the whole thing was full of sand and salt water. You could actually smell the ocean. It was like it had been drowned before. Dad said he'd shout me a carton if I clean it up for him so I spent two days with the bungs out and the hose getting every trace of sand out that I could. There was some form of prior rust protection there, but the sand had worked its way through that aswell and was making contact with the metal. So out it came. Dad spent about $450 on the ERPS and fitted it himself about 5 years ago and there has been no rust come through yet.

I'm about to pick up my new (old HJ60) next Saturday and I know what my first investment will be. I had a Hilux that I had repainted about 4 years ago and rust came through again after about 6 months after spending nearly $6000. I nearly cried. I wish I had have done it to that old girl. Like you said Spook, even if it makes that little bit of difference, I think it's worth it too. The amount of salt and sand that came out of Dad's car was frightening.

 

[Fuzzy Logic]

can't make any claims about whether the thing works, but at any rate the method asserted is capacitive coupling not impressed current cathodic protection -- which does indeed require grounding and is used successfully on ship hulls and gas pipelines etc.

Capacitive coupling, by contrast, purportedly retards rust formation by using vehicle paint as a dielectric to free electrons; it places the metal at a lower potential difference. The couplers are fixed to the vehicle's painted surface and are not sacrificial; the capacitive coupler is asserted to behave like the positive half of a capacitor.

What are the supposed limitations and caveats? The claim is that if the continuity of the painted surface is interrupted -- and this can happen from a stone chip or a paint crack -- the dielectric is broken, the charge is lost and so is any rust-retarding benefit (the CounterAct people dispute this claim). If this it true, the question would be how practicable it is to maintain eternal vigilance to assure the perfect continuity of your vehicle's painted surface.

The other assertion is that the technology is not suited to vehicles because of their irregular shapes and contours -- it's impossible to hold a charge on a thin and sharp metal surface.

On the other hand, CounterAct claims both lab and field testing back up their claims. In fact, though, some of the tests merely confirm that the method produces an electrostatic charge on a metal body and an alteration in the body's surface charge. Another test supposedly demonstrated that the charge was effected across "on the entire surface of a metal automobile body to which it was applied" and that "an alteration in the surface charge" was maintained "even at a distance from the capacitive coupler."

Three other tests -- by LACOR , Intertek/ETL and Canadian Tire -- were specifically about rust mitigation and migration. CounterAct claims these tests demonstrate an 80% reduction in the rate of corrosion. However, the tests were on painted automotive-grade steel panels -- if this refers to painted flat steel panels, this doesn't really answer the claim that sharp edges and irregular shapes mitigate the effectiveness of the method.

On the other, other hand, CounterAct claims field testing of the product under real-world conditions demonstrates its effectiveness. The "field-testing," though, is largely composed of fairly subjective anecdotal testimonials from satisfied customers ('our vehicles rust less than they used to' sort of thing), which is fine as far as it goes. It should be said that many of the testimonials are from people who don't appear to have used the unit for a long periods of time and so may not really be in a position to offer judgments on the long-term effectiveness of the product.

To sum up, then: a lot of the scepticism is a little misplaced because it's scepticism about a different method, cathodic protection. However, there are good reasons to be sceptical about this method as well -- more about the real-world effectiveness in use on motor vehicles than about whether it could work in principle. On the other hand, the company asserts that independent scientific testing and real-world use under harsher conditions than most vehicle owners will experience in fact validates their claims. However, on closer inspection, the applicability of at least some of the evidence on which their claims of effectiveness are based would appear somewhat more limited than appears at first blush.

I don't mean to cop out, but as for the real question -- will the damned thing work to slow rust if I install it on my car? -- my answer would have to be beats me. Somebody try it and let me know.

 

[donny paradise]

Would building a charge up on a car body would increase the risk of a static discharge when filling the fuel tank?

 

[gray]

MrMoMo,
I didn't read every word of every post, but what is the final answer; does anything work to slow down corrosion, other than coatings/paints? Can we just bolt a slab of ?magnesium to the frame and let that be used up instead of the steel/iron?

 

[grant5127]

Would building a charge up on a car body would increase the risk of a static discharge when filling the fuel tank?

You could drag a static chain behind your truck.......

 

[Fuzzy Logic]

Would building a charge up on a car body would increase the risk of a static discharge when filling the fuel tank?

Depends on how much voltage is created. Low enough voltage (like, say, 1V) and the risk is essentially zero. Of course, lower voltage also means less charge, so whether or not the thing can prevent rust effectively while still being at safe voltages remains a question.

 

[lathrop]

Interesting thread. I am familiar with impressed voltage anti galvanic corrosion devices on boats. I never heard of it for cars. As to the notion of the lack of electrolyte on cars, If you have salt on the roads and water trapped in crevices you you will get galvanic corrosion. Fish oil as mentioned is a good preventative. [ fisherman trick] As far as preventing the problem in cooling systems the addition of zinc anode to the radiator and to the engine should help with that. The plugs with anodes attached can be had at chandlers. [ boat store] Replacing the oil drain plug and the radiator drain plug with one of these couldn't hurt. and its cheap. Engine or cooling systems with magnesium alloys might benefit from magnesium anodes.