[165]

Hi,
Information on corrosion resistant paints and the chemistry of how they work seems to be farly scarse on the internet. If anyone knows where I could find some good diagrams, preferably refering to the corrosion of steel or iron in a marine environment showing how the use of these paints work, chemical equations, or even good descriptions of how the paints work (how it chemically bonds to the metal, movement of electrons, different types of paints etc.) then I would really apprecate you pointing me in the right direction in the form of websites or even giving me a basic understanding yourselves.

Thanks guys.

[RyanJones]

Well... here goes.

Corrosion in this case being rusting required 2 things, Oxygen and water, if either of thsoe are missing then Corrosin can't occur (I have proven this too myself by boinling water and putting a nain in it - no rust!)

Now, if the paint is un-broken then it will not allow either to get to the surface of the ircon and so it will not rust.

Another way is called sacrificial corrosion, a metal with a higher reactivity than the metal is placed in blocks on the less reactive metals surface. This metal then gets corroded instead of the less reactive metal. When the less reactive mettal is Iron then Zinc or Magnesium are commonly used

Cheers,

Ryan Jones

[mike]

(I have proven this too myself by boiling water and putting a nail in it - no rust!)

Why does a nail not rust in boiling water?

If this is true why do we need sacrificial anodes in our hot water service?

[RyanJones]

Why does a nail not rust in boiling water?

If this is true why do we need sacrificial anodes in our hot water service?

Put a pure Iron nail in boiled water and put a thin film of oil ober the top of it to stop more Oxygen dissolving and the nail will not rust.
We need sacrificial anodes in out water supplies because people would not be happy about having a layer of oil over all their water - well, I would not nayway  

Cheers,

Ryan Jones

[mike]

Oh, I misunderstood, you said that you put a nail in boiling water and it didn't rust. This is not the same as deoxygenating the water and putting oil on top. Interesting idea though.