Reading the instructions for the above re. preparation, a coat of
Sandtex Stabilising Solution is recommended to seal the surface before
application of the masonry paint itself.

Works OK, but the stabilising solution itself appears, superficially
at least, to be no more than a thin PVA solution. Does anyone know
whether this is, in fact, the case, or is it a more complex product
than that?

PVA would certainly be cheaper, but I'm not looking for false
economies.
..

Appelation Controlee wrote:
> Reading the instructions for the above re. preparation, a coat of
> Sandtex Stabilising Solution is recommended to seal the surface before
> application of the masonry paint itself.
>
> Works OK, but the stabilising solution itself appears, superficially
> at least, to be no more than a thin PVA solution. Does anyone know
> whether this is, in fact, the case, or is it a more complex product
> than that?
>
> PVA would certainly be cheaper, but I'm not looking for false
> economies.
> .
I didnt bother. used a thin coat first as sealer.

Got some spallation where water splash + frost got in: used some sort of
weathershield to fix that.

On 14/04/2011 21:40, Appelation Controlee wrote:
> Reading the instructions for the above re. preparation, a coat of
> Sandtex Stabilising Solution is recommended to seal the surface before
> application of the masonry paint itself.
>
> Works OK, but the stabilising solution itself appears, superficially
> at least, to be no more than a thin PVA solution. Does anyone know
> whether this is, in fact, the case, or is it a more complex product
> than that?
>
> PVA would certainly be cheaper, but I'm not looking for false
> economies.
> .

I'd say the stabiliser is probably an unpigmented version of the paint
itself, so more likely to be an acrylic. Could also be more penetrative
than pva

On Fri, 15 Apr 2011 09:42:45 +0100, stuart noble wrote:

> I'd say the stabiliser is probably an unpigmented version of the paint
> itself, so more likely to be an acrylic. Could also be more penetrative
> than pva

One way to find out what is in things is to look up the COSHH
datsheet on the product. The manufacturers web site should have them
available for download.

I was under the impression that you only needed to use the stabiliser
if the surface was powdery, ie rub your fingers along it and they get
covered in fine dust. I didn't use stabilser last year on our walls,
combination of pressure washed stone or painted render also pressure
washed to remove the loose paint. Did use a slightly diluted first
coat then two full strength, it has survived the winter...

--
Cheers
Dave.

On Fri, 15 Apr 2011 10:49:02 +0100 (BST), "Dave Liquorice"
<(E-Mail Removed)> wrote:

>On Fri, 15 Apr 2011 09:42:45 +0100, stuart noble wrote:
>
>> I'd say the stabiliser is probably an unpigmented version of the paint
>> itself, so more likely to be an acrylic. Could also be more penetrative
>> than pva
>
>One way to find out what is in things is to look up the COSHH
>datsheet on the product. The manufacturers web site should have them
>available for download.
>
>I was under the impression that you only needed to use the stabiliser
>if the surface was powdery, ie rub your fingers along it and they get
>covered in fine dust. I didn't use stabilser last year on our walls,
>combination of pressure washed stone or painted render also pressure
>washed to remove the loose paint. Did use a slightly diluted first
>coat then two full strength, it has survived the winter...

It is supposed to bind the surface, but my main concern is preventing
migration of staining from the surface being covered.

On 15/04/2011 14:35, Appelation Controlee wrote:
> On Fri, 15 Apr 2011 10:49:02 +0100 (BST), "Dave Liquorice"
> <(E-Mail Removed)> wrote:
>
>> On Fri, 15 Apr 2011 09:42:45 +0100, stuart noble wrote:
>>
>>> I'd say the stabiliser is probably an unpigmented version of the paint
>>> itself, so more likely to be an acrylic. Could also be more penetrative
>>> than pva
>>
>> One way to find out what is in things is to look up the COSHH
>> datsheet on the product. The manufacturers web site should have them
>> available for download.
>>
>> I was under the impression that you only needed to use the stabiliser
>> if the surface was powdery, ie rub your fingers along it and they get
>> covered in fine dust. I didn't use stabilser last year on our walls,
>> combination of pressure washed stone or painted render also pressure
>> washed to remove the loose paint. Did use a slightly diluted first
>> coat then two full strength, it has survived the winter...
>
> It is supposed to bind the surface, but my main concern is preventing
> migration of staining from the surface being covered.

Stabiliser always used to be solvent based, partly for that reason. I
don't know whether pukka paint outlets might still sell it

Appelation Controlee wrote:
> On Fri, 15 Apr 2011 10:49:02 +0100 (BST), "Dave Liquorice"
> <(E-Mail Removed)> wrote:
>
>> On Fri, 15 Apr 2011 09:42:45 +0100, stuart noble wrote:
>>
>>> I'd say the stabiliser is probably an unpigmented version of the paint
>>> itself, so more likely to be an acrylic. Could also be more penetrative
>>> than pva
>> One way to find out what is in things is to look up the COSHH
>> datsheet on the product. The manufacturers web site should have them
>> available for download.
>>
>> I was under the impression that you only needed to use the stabiliser
>> if the surface was powdery, ie rub your fingers along it and they get
>> covered in fine dust. I didn't use stabilser last year on our walls,
>> combination of pressure washed stone or painted render also pressure
>> washed to remove the loose paint. Did use a slightly diluted first
>> coat then two full strength, it has survived the winter...
>
> It is supposed to bind the surface, but my main concern is preventing
> migration of staining from the surface being covered.

I think a point needs making here. 'sealers' is a generic term, and in
this context there are two entirely different classes of product that do
two entirely different things. The binders, and the waterproof coatings


As far as the binders go, I find most professional painters simply use a
coat of thinned paint. Its shade more expensive, but it has got SOME
pigment in, and if a **** coat plus two coats rather than 3 coats
overall plus sealer is what it takes to get the color depth, its overall
cheaper probably.

Whilst paint or sealer does slow water uptake, it also slows water
egress, That means a painted sealed render is not that much better tan a
panted or indeed a bare render at frost attack.

And it can breathe and dry itself out.

If you go the weathershield or whatever route which puts an impermeable
layer in on the render surface, you will indeed completely stop water
getting in, but you may also stop it getting out if it gets behind the
sealed render surface.

My approach is to use the latter sparingly in places that are both cold
and subject to high water splash, ONLY where spallation has been
established as happening anyway. In my case that's the tops of lead
covered drip boards over the windows, on the house North side.

stuart noble wrote:
> On 15/04/2011 14:35, Appelation Controlee wrote:
>> On Fri, 15 Apr 2011 10:49:02 +0100 (BST), "Dave Liquorice"
>> <(E-Mail Removed)> wrote:
>>
>>> On Fri, 15 Apr 2011 09:42:45 +0100, stuart noble wrote:
>>>
>>>> I'd say the stabiliser is probably an unpigmented version of the paint
>>>> itself, so more likely to be an acrylic. Could also be more penetrative
>>>> than pva
>>>
>>> One way to find out what is in things is to look up the COSHH
>>> datsheet on the product. The manufacturers web site should have them
>>> available for download.
>>>
>>> I was under the impression that you only needed to use the stabiliser
>>> if the surface was powdery, ie rub your fingers along it and they get
>>> covered in fine dust. I didn't use stabilser last year on our walls,
>>> combination of pressure washed stone or painted render also pressure
>>> washed to remove the loose paint. Did use a slightly diluted first
>>> coat then two full strength, it has survived the winter...
>>
>> It is supposed to bind the surface, but my main concern is preventing
>> migration of staining from the surface being covered.
>
> Stabiliser always used to be solvent based, partly for that reason. I
> don't know whether pukka paint outlets might still sell it

Many types exist. The weatheshield types are I think solvent based or
actual cold set resins of some sort.

They will stop staining, but they will also stop a wet render drying. So
be careful.

On Apr 14, 9:40*pm, Appelation Controlee <m...@privacy.net> wrote:
> Reading the instructions for the above re. preparation, a coat of
> Sandtex Stabilising Solution is recommended to seal the surface before
> application of the masonry paint itself.
>
> Works OK, but the stabilising solution itself appears, superficially
> at least, to be no more than a thin PVA solution. Does anyone know
> whether this is, in fact, the case, or is it a more complex product
> than that?
>
> PVA would certainly be cheaper, but I'm not looking for false
> economies.
> .

Its a false economy to use paint that doesn't last well. I found Dulux
has lasted where the various screwfix ones haven't.


NT

On Fri, 15 Apr 2011 17:48:42 +0100, The Natural Philosopher
<(E-Mail Removed)> wrote:

>Appelation Controlee wrote:
-----------------------------8><
>> It is supposed to bind the surface, but my main concern is preventing
>> migration of staining from the surface being covered.
>
>I think a point needs making here. 'sealers' is a generic term, and in
>this context there are two entirely different classes of product that do
>two entirely different things. The binders, and the waterproof coatings
>
>
>As far as the binders go, I find most professional painters simply use a
>coat of thinned paint. Its shade more expensive, but it has got SOME
>pigment in, and if a **** coat plus two coats rather than 3 coats
>overall plus sealer is what it takes to get the color depth, its overall
>cheaper probably.
>
>Whilst paint or sealer does slow water uptake, it also slows water
>egress, That means a painted sealed render is not that much better tan a
>panted or indeed a bare render at frost attack.
>
>And it can breathe and dry itself out.
>
>If you go the weathershield or whatever route which puts an impermeable
>layer in on the render surface, you will indeed completely stop water
>getting in, but you may also stop it getting out if it gets behind the
>sealed render surface.
>
>My approach is to use the latter sparingly in places that are both cold
>and subject to high water splash, ONLY where spallation has been
>established as happening anyway. In my case that's the tops of lead
>covered drip boards over the windows, on the house North side.

Thanks - taken under consideration. :-)