I just posted a thread about a possible overcharging problem. While I was researching that topic, I ran across several on radiator electrolysis. I did the test and came up with 1.5 V on DC and .37V on AC on the meter. I also did a continuity test between the negative battery post and the radiator neck (a bare spot where the cap had worn the paint off) and I did get a tone - meaning there was a circuit.

Do I have a potential or actual electrolysis problem here? I just installed a new Dewitts radiator and I sure don't want to ruin that brand new expensive radiator!!!

Thanks,

Terry

 

Radiator electrolysis isn't an issue on millions of new cars with aluminum radiators, and they don't use any of the "miracle anode" fixes; I wouldn't worry about it.

 

However, they do have a ground wire or some other means of making sure that the radiator isn't isolated from the ground. There have been many cases of collision damage being repaired and this item overlooked and the radiator is in deed eaten up in a short period of time. Most, if not all, body shops are aware of this.

Jim

 

Strange..in all the new cars I've ever replaced radiators at my shop (plenty!!) I have NEVER seen a ground wire.

Never saw a warning that it would void the warranty on a new one

Also most cars have plastic tanks and mount in rubber bushes, like perfect insulators...and have no problems

 

That's odd because every manufacturer of radiators, including Griffin and DeWitts, address this issue. I was reading an industry journel while waiting to pick up my wife's car at the body shop and there was an article about this topic. That got me thinking about my Cobra and when I did a search on it on the kit car forums, everyone says to make sure your rad. is grounded to prevent electrolysis.
Here's some links if you want to expand your knowledge on the subject:
http://www.carolinarodshop.com/Store...ectrolysis.htm
http://www.rondavisradiators.com/tech.htm
http://www.birdsradiator.com/electrolysis.nxg
http://www.sancarlosradiator.com/electrolysis.htm
Here's a good one about why his new rad. came with a ground wire - http://forums.corral.net/forums/gene...-radiator.html

You may not have had problems but the rest of the planet is well aware of the issue. Glad I never went to your shop for a repair.

Jim

 

Ok, now I'm confused. This is a very interesting topic and something I think most of us could benefit from so I hope the discussion doesn't descend into an argument. I am not picking sides here, just curious of the best way to go. I did browse through some of the links provided above but most seemed to advise against grounding the radiator. For example:

"Early on, when electrolysis first cropped up as a problem in cooling systems, many mechanics attempted to solve the problem by grounding the heater or radiator in order to "collect" any stray voltage and route it to battery ground. But mechanics soon discovered that grounding a heat exchanger to "collect" stray current merely accelerated the damage to the heat exchanger. What they really needed, they found, was a way to draw the stray voltage away from the heat exchanger, similar to what boaters do when they install "sacrificial" zinc anodes that collect and dissipate stray electrical current before it chews up a boat's engine, propeller, or metal hull."

That quote comes from one of the referenced posts. So...is grounding a good thing or a bad thing? (I found similar information on the post from Griffin Radiators. I recently installed a DeWitts radiator which I am very pleased with. I don't recall any direction to ground the radiator at installation. Perhaps DeWitts will opine on the subject.)

Thanks for bringing this up!

 

Electrolysis has nothing to do with battery voltage or "stray current". It is caused by galvanic action where the more reactive metal (aluminum or brass) is sacrificed in order to "spare" the less reactive metal (cast iron).

Look up "galvanic cell" for an explanation. The coolant is the electrolyte, the engine block, iron heads, iron intake manifold and water pump are the cathodes and the radiator is the anode.

If both the engine block and radiator are grounded, the circuit is completed and galvanic action can begin.

 

That is my understanding. The cure is to flush and refill coolant at regular intervals before it becomes acidic and then promotes electrolysis.

 

I agree completely with this reasoning. And for anecdotal evidence that it is the right way to think about the grounding question, consider that the Corvette aluminum radiators since '63 were mounted in insulating rubber cushions. A lot of these original radiators remain intact nearly 50 years later.

Where this goes screwy, though, is that some modern radiator hoses are ever so slightly conductive, thereby completing the circuit and promoting galvanic corrosion, albeit very slowly.

Jim

 

I found a link to the article I referred to above that was in "Automotive Body Repair News". It explains everything you need to know about this problem. Pay attention to the part that says: "Serious problems with stray-current electrolysis can occur when the cooling system is not grounded or when an ungrounded electrical device is part of the vehicle's operating system."

http://www.erareplicas.com/427man/co...ysis/index.htm

You can do whatever you want but when I put a $1000 radiator in my car, I make sure it's grounded. I also use a zinc anode in the drain plug (that comes from 30 years of owning boats).

Jim

 

I'm following up on my original post. I called Dewitts to see what they had to say about the electrolysis. They said they had only two calls about it in the past year, so they didn't have any real definitive answers.

After I solved my concurrent overcharging problem, I ran every conceivable voltage check I could think of - from the battery to the coolant, radiator to coolant, block to coolant, all of those with the battery disconnected, all with engine off, all with engine running, etc. I've got three handwritten pages of readings!

All but one of my readings was from .00V to .04v. I got one reading with .20V for whatever reason. BTW, I questioned if my multi-meter was working correctly (it had been acting a little weird after I put a new battery in it), so I used my dad's meter. I think my initial readings were due to faulty test equipment. Since I had no readings anywhere near the so-called threshold for electrolysis, I've gone on to other things on the car.

I'm just wondering out loud here and don't really need an answer, but how can my radiator ('60) be totally isolated when the radiator bolts also go through the shroud holes which in turned are bolted tightly to the frame? I'm far from an electrical engineer, but my frame is grounded and the aluminum radiator is connected to that ground via sheet metal and bolts. So one of the dozens of articles I read about electrolysis that said NEVER to use the radiator as a ground seems not only contradictory but practically impossible to achieve. At least it seems that way to me.

For now, I'm satisfied that I don't have a problem. I'll probably check it from time to time to make sure nothing crops up, but I'm going to put this one to rest.

Thanks for the help!

Terry

 

If you read the article, it says that using the radiator as a ground for electrical accessories is bad, it doesn't say anything about having to ground the radiator to prevent general galvanic action.

Other than possible grounding through the metal anti collapse spring in the lower radiator hose, no GM radiator has been grounded, as it came from the factory, at least up through the mid 1970's, and they never had problems.

Doug

 

Grounding a radiator didn't become a big issue until the 80's when they started using composite tanks that totally isolated the aluminum core from the ground. Prior to that, it would be almost impossible to install a rad. and not have it grounded. Just like those that say "don't use sealer or teflon tape on a temp. sending unit as it will screw up the readings". That's total B.S. There is no way you can install the sending unit and not have it grounded no matter how much sealer you use.
The article clearly states the need to ground the rad. to prevent electrolysis. I suggest you read the article again.
Electrolysis is a documented problem and there's a simple solution. Do whatever you want. I'm done with this topic.

Jim

 

actually it is true but the issue is not about grounding but resistance

 

Believe what you want.

A factory C1 radiator is ungrounded from the factory. Period.

The Original, as in 1961 original, aluminum radiator I replaced in 2008, was still fine after 45 years, though i didn't trust its ability to work with the 427 SB I installed at that time. And I went decades with out changing the coolant. I also replaced the 35 year old expansion tank, though it was also fine, but not as pretty as i wanted

The radiator is isolated from the frame by three rubber donuts. My personal feeling is that this rubber mounting has more to do with isolating the radiator from frame flex or vibration, than electrical isolation, as the c1 remote expansion tank, also is made out of aluminum and is bolted directly to the exhaust manifold, one is grounded, one isn't, neither one seems to be getting eaten away.

I do not really believe in aluminum radiator electrolysis; though, as the mag article stated, if you try and ground some electrical gizmo, like an electric fan through the radiator, you could end up with problems.

Doug

 

so electricity does not flow through antifreeze?

 

I agree with Jim. Take a look at page 8 of this file
http://www.lbfun.com/warehouse/tech_...eCF-Thread.pdf