I have used both but don't really know the difference. OSPHO is Phosphoric
acid. It is applied to rusty metal and let dry. It forms a white power
which is just wiped off. The underlying coating on the metal is iron
phosphate I believe which is iron oxide (rust) converted to a non ferrous
and will not rust. It isn't a durable coating so it must be painted.
Paint and body shop suppliers sell it in a very diluted form as a metal
prep. I have used if for years and keep it around to prep rusty surfaces.
It won't fix rust scale though. That must be chipped off.
The Phosphate wash I believe leaves a black coating on the metal which is
again a non ferrous.
Joe Worsley
80 Tr8
72 TR6
Advance, NC
>
> Hi List,
> Does anyone know the differance between a "metal phosphate
>wash" and the product OSPHO? The powdercoater says its not the same thing.
>Thanks in advance.
>
>
>
>PLB3
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