Sacrificial Anode

[cudabob496]

I know we discussed this before, but in a new car mag I just got, they recommend a sacrificial anode (probably zinc) in the
coolant system, just under the radiator cap, so that electrolysis will not cause aluminum to be consumed/corroded.  I'm gonna have to
look into this more, as I have alum heads and water pump.


http://www.summitracing.com/parts/flx-32060/overview/

http://www.summitracing.com/parts/sdk-c5zz8100rce/overview/

The article also said that if you have a battery disconnect switch on you negative cable, then having that open, when car is parked,
may also help reduce aluminum corrosion due to electrolysis.

I decided to buy the first part listed above. Gonna stick it in the water pump housing.

[dodj]

Well they are effective in potable hot water systems and outboard motors. Don't see why it wouldn't be effective in motor coolant, unless the coolant behaves differently than straight water with respect to electrolisis.

[cudabob496]

Well they are effective in potable hot water systems and outboard motors. Don't see why it wouldn't be effective in motor coolant, unless the coolant behaves differently than straight water with respect to electrolisis.

the other thing is the coolant has 12 volts running through it, which helps accelerate the corrosion process.
If the coolant had no minerals or chemicals in it, then electrolysis would not occur, but that is not the case.

I'll do whatever I can to keep from having to rebuild this engine any sooner than I have to! No money!!

[73EStroker]

Don't know if you're being a little anxious about this as there are cars around that are 40+ years old that have aluminium engine components. Only thing I am aware of is not to let the antifreeze get acidic. I avoid that by changing it every two years

[cudabob496]

Don't know if you're being a little anxious about this as there are cars around that are 40+ years old that have aluminium engine components. Only thing I am aware of is not to let the antifreeze get acidic. I avoid that by changing it every two years

the article below seems to be common on the web. I figure the $25 zinc sacrificial anode I bought from Summit
is cheap insurance.

http://www.aa1car.com/library/cooling_system_electrolysis_corrosion.htm

[HP_Cuda]

Ideally you isolate the current from the aluminum radiator and keep electrolysis from happening at all!

[cudabob496]

Ideally you isolate the current from the aluminum radiator and keep electrolysis from happening at all!

But then you have the aluminum heads and waterpump to deal with.

[06Daytona]

A zinc anode won't work on aluminum. The aluminum will actually sacrifice itself for the zinc. Zinc anodes are used to avoid corrosion on mild steel but the atomic number, or whatever number is used to determine what will sacrifice for what ( I can't remember right now, but I wrote a report on it in school) is lower on aluminum than it is on zinc.

[EB3-GranCoupe]

http://en.wikipedia.org/wiki/Cathodic_protection

http://en.wikipedia.org/wiki/Galvanic_corrosion

Magnesium would work best.

[72cudamaan]

http://en.wikipedia.org/wiki/Cathodic_protection

http://en.wikipedia.org/wiki/Galvanic_corrosion

Magnesium would work best.

According to the chart, the way I read it, zinc is the best option.

For normal environments, such as storage in warehouses or non-temperature and humidity controlled environments, there should not be more than 0.25 V difference in the "Anodic Index". For controlled environments, in which temperature and humidity are controlled, 0.50 V can be tolerated. For harsh environments, such as outdoors, high humidity, and salt environments, there should be not more than 0.15 V difference in the "Anodic Index". For example; gold/silver would have a difference of 0.15V being acceptable

[cudabob496]

According to the chart, the way I read it, zinc is the best option.

For normal environments, such as storage in warehouses or non-temperature and humidity controlled environments, there should not be more than 0.25 V difference in the "Anodic Index". For controlled environments, in which temperature and humidity are controlled, 0.50 V can be tolerated. For harsh environments, such as outdoors, high humidity, and salt environments, there should be not more than 0.15 V difference in the "Anodic Index". For example; gold/silver would have a difference of 0.15V being acceptable

Could the battery be putting 12 volts through the coolant?

[EB3-GranCoupe]

Could the battery be putting 12 volts through the coolant?

I would think so, especially if all of the ground locations are in good contact.  Disconnecting the battery when not in use should help alleviate that condition.

[HP_Cuda]

Well, let's take a look:

1)Negative battery cable is hooked up to the block or a framepoint
2) All you need is to close the loop and wallah you have current flowing through your radiator because guess what your radiator is in direct contact with the frame!
3) From what I have read if you can keep your current below .45V in your coolant you will be fine. I actually had one car recently which was reading .800V and I isolated the aluminum rad from the frame and bam it dropped to the safe zone.

B

[cudabob496]

here's another consideration. how many thousands of volts do you have across your spark plug, which is grounded to the head,'
which has coolant inside it.  I just got my zinc anode from Summit. I'll put it in the water pump housing, and check it in a year to see
if it is corroding. If so, that means aluminum and iron is not corroding, at least not as much.

[cudabob496]

and the guys with the all aluminum hemis might even have a bigger challenge, corrosion wise!