Sulphate of Iron stain on house
ofn01
We were doing some moss control using sulphate of iron disolved in water but
splashed some on the cladding which has left a yellow stain.
How can this stain be removed?
Google has results for removing the stain from concrete using a baking soda
mixture but I am not sure if this is suitable for wood?
Me
work.
Oxalic acid should work (but that really shouldn't be used on concrete)
You can buy oxalic acid crystals at some hardware stores - it's used for
bleaching wood. Alternatively, there's a product available from boat
stores which used to be called "Emergel" now called "Grunt" cleaner,
which is based on oxalic acid plus surfactants. Wipe the gel on, let it
react, and clean it off very thoroughly before repainting or whatever.
Don't let it dry on the surface.
Nicolaas Hawkins
<news:h8q3he$53p$1...@news.albasani.net>:
One should perhaps add that oxalic acid is extremely toxic. It is, amongst
other things, the poisonous principle in rhubarb leaves.
--
- Nicolaas
Warwick
Paint over. pig seal the spot (e.g. resene sureseal) then
spot paint over twice with top coat. Probably wont come off
without damaging the paint anyway, so if you have to repaint
anyway...
Me
So long as you don't drink the solution and wash any off your hands
(pref. wear gloves when using it) it's not problem. Janola, turps,
drain cleaner - lots of common garden and household chemical formulas
are poisonous.
It is darned good stuff for removing iron and rust stains, and mild
solutions are not too damaging on paint etc - so long as you rinse it
off well.
Reading the wiki article on it, it's apparently used in wart remover!
(but no cite on the wiki quote).
My son, when about 8YO had warts and verrucae all over his feet. After
several trips to the Dr to have them treated (only to grow back), and
several completely unsuccessful (and expensive) OTC topical treatments
from the chemist shop, we tried the old banana peel treatment. (I'm a
real sceptic on this sort of thing). Cut pieces of banana peel, and
tape it - inside surface down - over verruca, leave it on several days,
replacing with fresh banana skin after bathing etc. After about 3 days,
the verucca goes black, starts shrinking and pulling away from the skin.
After about a week, they'd all gone, and they never came back. Yep -
it's an anecdote with no scientific test, and only some loose theory
about potassium and/or enzymes in the skin killing the warts. It's
possible that the treatment coincided with the immune system kicking in,
and they would have gone away without treatment anyway. But I was
pretty impressed - the hardest part was convincing an 8yo that bits of
banana peeled taped to your feet was a sensible thing for adults to
force on a child.
ofn01
"Warwick" <no...@nowhere.com> wrote in message
news:9fswpbmcsm36$.178mscop34q1r$.dlg@40tude.net...
So paint over the stain directly.
Then put sureseal on
Then paint over twice again?
Why can't I just paint once over the stain?
Warwick
No. rub most of the stain out with sandpaper. put one coat
of pigmented sealer over the stain. Then two top coats over
the pig seal.
If its glossy - sonyx or whatever - then its probably going
to look fucked no matter what but will settle down over
time. Touch ups only really work with lo sheen paints but
the only alternative is repainting the whole wall. Touch it
up and let it settle down is my advice.
--
cheers
ofn01
What is it about painting directly on top of the stain that is bad?
Me
> "Warwick" <no...@nowhere.com> wrote in message
> news:1357rhfc8fkhn.a9hya9i0uarx$.dlg@40tude.net...
>> On Thu, 17 Sep 2009 18:00:07 +1200, ofn01 wrote:
>>
>>> "Warwick" <no...@nowhere.com> wrote in message
>>> news:9fswpbmcsm36$.178mscop34q1r$.dlg@40tude.net...
>>>> On Wed, 16 Sep 2009 17:40:19 +1200, ofn01 wrote:
>>> So paint over the stain directly.
>>> Then put sureseal on
>>> Then paint over twice again?
>>>
>>> Why can't I just paint once over the stain?
>> No. rub most of the stain out with sandpaper. put one coat
>> of pigmented sealer over the stain. Then two top coats over
>> the pig seal.
>>
>> If its glossy - sonyx or whatever - then its probably going
>> to look fucked no matter what but will settle down over
>> time. Touch ups only really work with lo sheen paints but
>> the only alternative is repainting the whole wall. Touch it
>> up and let it settle down is my advice.
>>
>
> What is it about painting directly on top of the stain that is bad?
>
>
resin binders contain "coalescing solvents" (usually glycol ethers -
which act to bind the acrylic resins together after the water
evaporates) which remain in the "dry" paint film for days or weeks, and
will tend to draw soluble stains through the paint film. Some sealers
might work, as they'd dry (without use of "coalescing solvents") and act
as a barrier to (hopefully) stop the stain from migrating though the
paint film.
You could try painting layer upon layer of paint (without sealer) until
the stain migration stops, but it could be a hiding to nowhere.
Oil based paint might be better, but then again it might not be, and if
it's not, then you've got a right pickle to sort out.
Judges 13:18
> Cut pieces of banana peel, and
> tape it - inside surface down - over verruca, leave it on several days,
Would you, please, clarify: Is it inside surface of banana peel in
contact with skin?
Thanks in advance.