hi all,i put rust remover on some galvanised metal and it worked a
treat,i washed it with soapy water but now it has dried there is
patches of white powder,is there anything i can use to halt the
reactin continuing,many thanks

On Jun 12, 8:20*am, bob wrote:
hi all,i put rust remover on some galvanised metal and it worked a
treat,i washed it with soapy water but now it has dried there is
patches of white powder,is there anything i can use to halt the
reactin continuing,many thanks

rust remover tends to be phosphoric acid, so baking soda or washing
soda.


NT

"bob" wrote in message
...
hi all,i put rust remover on some galvanised metal and it worked a
treat,i washed it with soapy water but now it has dried there is
patches of white powder,is there anything i can use to halt the
reactin continuing,many thanks


Usually phosphates, but they create a passive 'ready oxidised' surface (If
you are really brave, you can get an even more passive finish - but not on
your zinc coated stuff I suspect - with fuming nitric acid. It is quite a
surprise to dunk some iron into this and not have it instantly froth up.)

Trouble is, if you succeed in washing it off, it'll probably rust again.
On the other hand, leave it, and the paint doesn't stick properly.
In the end I used to find that, 'red lead' straight on the cleaned metal was
the most effective preparation.

(Also note that with the typical dimpled 'Hammerite' finish, there is nearly
always a little 'fish-eye' of uncoated metal, that rusts. Used to try all
sorts of additives to prevent the dimples developing into fish-eyes, but
rarely managed it, so smooth is best if you want rust resistance.)

S

On Jun 12, 4:59 pm, "spamlet" wrote:
"bob" wrote in message

...

hi all,i put rust remover on some galvanised metal and it worked a
treat,i washed it with soapy water but now it has dried there is
patches of white powder,is there anything i can use to halt the
reactin continuing,many thanks

Usually phosphates, but they create a passive 'ready oxidised' surface (If
you are really brave, you can get an even more passive finish - but not on
your zinc coated stuff I suspect - with fuming nitric acid. It is quite a
surprise to dunk some iron into this and not have it instantly froth up.)

Trouble is, if you succeed in washing it off, it'll probably rust again.
On the other hand, leave it, and the paint doesn't stick properly.
In the end I used to find that, 'red lead' straight on the cleaned metal was
the most effective preparation.

(Also note that with the typical dimpled 'Hammerite' finish, there is nearly
always a little 'fish-eye' of uncoated metal, that rusts. Used to try all
sorts of additives to prevent the dimples developing into fish-eyes, but
rarely managed it, so smooth is best if you want rust resistance.)

S

I find 2 coats (as per destructions) covers 99.9% satisfactorily...

cheers
Jim K