[Boatanchors] Rust, Coatings, etc.

[David C. Hallam]

The problem with rust is that it is not a tightly adhering surface and 
will scale off exposing a fresh surface to start further rusting. The 
surface of Cor-Ten formed on weathering is tightly adhering and stops 
further rusting.

David
KW4DH


On 4/7/2013 11:44 PM, Bill Carns wrote:
> Certainly, and you have too. It is called Gun Blue. Gun Blue is nothing more
> or less than carefully applied rust - applied to a very well polished
> surface in a very controlled way to produce a layer thickness that refracts
> light and makes it look Blue.
>
> Rust is a great passivation for steel and it is a very misunderstood process
> and situation.
>
> By the way, the US Navy uses Ospho on their rusty surfaces to terminate the
> rust process before they paint and it works well.
>
> The problem with rust is that if you try and paint over it without
> terminating the oxidation process, then you get way worse pitting and
> potential structural damage.  I use Ospho on my tower components and it
> works very well.  I Ospho and then use a Zinc rich paint over that and it
> works well and holds up well.
>
> Bill
>
>

-- 
“One of the evils of democracy is, that you have to put up with the man you elect whether you want him or not.”  Will Rogers