Graphite Used As A Corrosion Inhibitor 1

[myredrocket7]

Has anyone ever heard of adding a small quantity of graphite to an automotive cooling system to inhibit corrosion?
I discovered the attached link, which describes it, but can find no other references to the practice anywhere.
I wouldn't expect the idea to be much of a money maker for any company, considering the price of graphite and the quantities involved, so that's not much of a motivation.
It does seem that their 'research' is purely anecdotal, does anyone think it makes any scientific sense?

http://www.malibuwater.com/graphite.html

 

[CoryPad]

It makes no sense, scientifically. Graphite is highly cathodic to all common metals in water solutions, making galvanic corrosion highly likely. The proposed mechanism of preventing oxygen from reaching the metal is ridiculous.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[strider6]

i agree, i don't see how it can works..
it seems that the mechanisms of corrosion prevention is that the graphite will coat the entire internal surface preventing oxygen to reach the surface.
I don't understand how graphite added to the fluid will reach and coat the entire surface...

S.

Corrosion Prevention & Corrosion Control

 

[brimmer]

I am skeptical as well, the first thing as pointed out by CoryPad is graphite would be highly cathodic to any metal you would find in a radiator, making galvanic corrosion a possiblility. The next question I would have is how exactly does the graphite bond to the surface of the metal? And the next, it states it would bond even if there was corrosion (and depostis), I am skeptical of this as well, or at least that it would stay bonded as corrosion would continue to some extent under the graphite. I notice that it is always is recommending a flush before application, which would probably alone increase performance of the system.
Also, anitfreeze already contain corrosion inhibitors which coat the surface of the metal...

 

[NickE]

Just to add to this: read here:

thread71-226202



Nick
I love materials science!

 

[unclesyd]

I think where the use of graphite is coming from is in years past there were several types of radiator stop leak that used graphite and asbestos as the main ingredients.
There were claims that these products also help prevent corrosion to the cooling system, also lubricated the water pump.

I have two of these cubes in a box in my shop desk.

 

[knowlittle]

Whoever wrote the linked article must have something against science. Maybe her/his ex was a scientist.