Hello,

I know you can get a black "paint" to paint over rust, but how does it
work and is it any better than using normal gloss paint? Presumably
forming a barrier to stop water getting in is half the battle?

The one I have seen is bizarrely water based, I would have thought
water is the last thing you want to apply to rust! I know they are not
quite the same but the Ronseal and Hammerite metal paints that are
supposed to stop rust forming in the first place require a special
solvent, don't they.

Thanks.

On Jun 19, 10:29*am, Fred wrote:

Hello,

I know you can get a black "paint" to paint over rust, but how does it
work and is it any better than using normal gloss paint? Presumably
forming a barrier to stop water getting in is half the battle?

The one I have seen is bizarrely water based, I would have thought
water is the last thing you want to apply to rust! I know they are not
quite the same but the Ronseal and Hammerite metal paints that are
supposed to stop rust forming in the first place require a special
solvent, don't they.

Thanks.



The best rust treatments contain phosphoric acid in water. This
converts existing rust to a stable compound (iron phosphate I guess).


NT

On 19 Jun, 17:23, wrote:

The best rust treatments contain phosphoric acid in water. This
converts existing rust to a stable compound (iron phosphate I guess).

Sounds like Coca Cola to me. At last, a use for the stuff, I certainly
wouldn't risk drinking it.

wrote:
On Jun 19, 10:29 am, Fred wrote:

Hello,

I know you can get a black "paint" to paint over rust, but how does it
work and is it any better than using normal gloss paint? Presumably
forming a barrier to stop water getting in is half the battle?

The one I have seen is bizarrely water based, I would have thought
water is the last thing you want to apply to rust! I know they are not
quite the same but the Ronseal and Hammerite metal paints that are
supposed to stop rust forming in the first place require a special
solvent, don't they.

Thanks.



The best rust treatments contain phosphoric acid in water. This
converts existing rust to a stable compound (iron phosphate I guess).


NT
Neither water nor air cause rust. Its both together. Or water plus some
other oxidant like whatever seawater has in it.


Eliminate either one and you are on a winner.

Martin Pentreath wrote:

On 19 Jun, 17:23, wrote:


The best rust treatments contain phosphoric acid in water. This
converts existing rust to a stable compound (iron phosphate I guess).


Sounds like Coca Cola to me. At last, a use for the stuff, I certainly
wouldn't risk drinking it.

But doesn't coca cola rust/rot the gut? I wouldn't risk drinking it either.

Dave

On Jun 19, 6:30*pm, Martin Pentreath
wrote:
On 19 Jun, 17:23, wrote:

The best rust treatments contain phosphoric acid in water. This
converts existing rust to a stable compound (iron phosphate I guess).

Sounds like Coca Cola to me. At last, a use for the stuff, I certainly
wouldn't risk drinking it.

far too weak unfortunately


NT

Dave wrote:
Martin Pentreath wrote:

On 19 Jun, 17:23, wrote:


The best rust treatments contain phosphoric acid in water. This
converts existing rust to a stable compound (iron phosphate I guess).


Sounds like Coca Cola to me. At last, a use for the stuff, I certainly
wouldn't risk drinking it.

But doesn't coca cola rust/rot the gut? I wouldn't risk drinking it either.

Dave

Ah - but our CC doesn't contain high fructose corn syrup (like it does
over there - but not the passover version IIRC).

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

On Jun 19, 6:59 pm, The Natural Philosopher wrote:
On Jun 19, 10:29 am, Fred wrote:

I know you can get a black "paint" to paint over rust, but how does it
work and is it any better than using normal gloss paint? Presumably
forming a barrier to stop water getting in is half the battle?

The one I have seen is bizarrely water based, I would have thought
water is the last thing you want to apply to rust!

Neither water nor air cause rust. Its both together. Or water plus some
other oxidant like whatever seawater has in it.

The oxidant in sea-water is just dissolved or entrained air. The
reason sea-water is so powerful at rusting is that it contains
chloride ions which either make the rust layer more permeable, or
catalyze the process (I can't remember which now - it's more than a
quarter century since I did Metallurgy!).


Eliminate either one and you are on a winner.

Quite - which is why the Titanic hasn't turned into a pile of brown
sludge - the air can't get to it, so it doesn't rust.