Are proprietary 'Stain block' paints any better than oil-based undercoats?
--
Jim
Tyneside UK

"Jim Scott" wrote in message
...
Are proprietary 'Stain block' paints any better than oil-based undercoats?
--
Jim
Tyneside UK

Can't say i've ever used an under coat for stain blocking. What I do use is
Screwfix's spray stain block, which is very easy to use and drys quickly.
Most likely a lot quicker then an oil based paint.

On Thu, 08 Sep 2005 12:20:56 +0100, Jim Scott
wrote:

Are proprietary 'Stain block' paints any better than oil-based
undercoats?

I first read that as "Satin black". They do more or less what it says on
the tin, although I had an uber-stain which required three coats of the
Aquaseal product to kill it.

John Schmitt

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Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

In article ,
says...
Are proprietary 'Stain block' paints any better than oil-based undercoats?

For what?

On Thu, 8 Sep 2005 15:53:15 +0100, Rob Morley wrote:

In article ,
says...
Are proprietary 'Stain block' paints any better than oil-based undercoats?

For what?

Skid marks )

Nah; really water marks on the ceiling after a roof leak.
--
Jim
Tyneside UK

"Rob Morley" wrote in message
...
In article ,
says...
Are proprietary 'Stain block' paints any better than oil-based
undercoats?

For what?

Presumably for blocking stains.

Jim Scott wrote:
Are proprietary 'Stain block' paints any better than oil-based undercoats?

I have used the stain block that Screwfix sell to cover water marked
plaster. I found the yellowing stain came through the stain block as
well, which looked suspiciously like normal emulsion to me. Eventually
I managed to cover it, but it took several coats of stain block and
several more coats of normal emulsion (Dulux trade satin).

Make of that what you will.

--

Steve F

In article ,
says...
On Thu, 8 Sep 2005 15:53:15 +0100, Rob Morley wrote:

In article ,
says...
Are proprietary 'Stain block' paints any better than oil-based undercoats?

For what?

Skid marks )

Nah; really water marks on the ceiling after a roof leak.

I reckon an oil-based wood primer will take care of that.

In article , says...

"Rob Morley" wrote in message
...
In article ,
says...
Are proprietary 'Stain block' paints any better than oil-based
undercoats?

For what?

Presumably for blocking stains.

What sort of stain, what sort of surface ...

"Jim Scott" wrote in message
...
Are proprietary 'Stain block' paints any better than oil-based undercoats?
--
I used Dulux (I think) stain block in the airing cupboard to cover stains
from a leaking pipe in the loft. Initially applied normal Dulux matt
emulsion but stain came back. Used stain block + emulsion and no sign of any
stains.

I have also heard this being used to cover nicotine stains as well.

Jim Scott wrote:
Are proprietary 'Stain block' paints any better than oil-based undercoats?

Yes. Oil based undercoat will block some stains, stain block will
handle more.

NT

wrote:
Jim Scott wrote:

Are proprietary 'Stain block' paints any better than oil-based undercoats?


Yes. Oil based undercoat will block some stains, stain block will
handle more.

NT


The only stains I've come across are from old water leaks. I guess the
reason they're always brown is either that they carry rust from fixings
in the masonry or oxides from the bricks. Maybe John Schmitt can
enlighten us on that.
Any oil based paint will block these, but any water based coating won't
IME.

"Zinnser" (sp?) is very good. I used it over 3 month old creosote which
I then white emulsioned, and nothing came through in 3 years!

On 8 Sep 2005 12:10:06 -0700, Mr Fuxit wrote:

"Zinnser" (sp?) is very good. I used it over 3 month old creosote which
I then white emulsioned, and nothing came through in 3 years!

Has anyone used Wilkinson's own brand Stain Block?
I use their paint all the time and find the covering power excellent.
However the stain block (water based) is still showing the colour through
after two coats.
I don't really want to emulsion over it until I'm sure.
--
Jim
Tyneside UK

On Thu, 08 Sep 2005 18:44:37 +0100, Stuart Noble
wrote:

The only stains I've come across are from old water leaks. I guess the
reason they're always brown is either that they carry rust from fixings
in the masonry or oxides from the bricks. Maybe John Schmitt can
enlighten us on that.

It is normally hydrous iron oxides from either source carried by water
ingress. In short they both count as rust stains. Chemically there is
little to differentiate them, although it is a matter of some puzzlement
to me as to why these stains can penetrate an oil-based medium. I can only
conjecture that the ferric ion complexes with the part of the solvent
matrix and migrates in this manner. Iron does some bizarre things, like
form ferrocene. My best guess is that the reason for this is that there
are only 2 electrons in the outer shell, leaving the 14 in the next shell
down accessible thus resulting in this anomalous behaviour.

John Schmitt

--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

Fitz wrote:
Jim Scott wrote:
Are proprietary 'Stain block' paints any better than oil-based undercoats?

I have used the stain block that Screwfix sell to cover water marked
plaster. I found the yellowing stain came through the stain block as
well, which looked suspiciously like normal emulsion to me. Eventually
I managed to cover it, but it took several coats of stain block and
several more coats of normal emulsion (Dulux trade satin).

Make of that what you will.

--

Steve F

I used Zinnser BIN Stain block to cover nicotine staining. A small can
which didn't cover anything close to the area written on the tin and
the stains also came through again.

Ended up using a wood undercoat and it worked perfectly.

However the stain block (water based) is still showing the colour through
after two coats.

As far as I am concerned, no water based stain block can be as
efficient as a spirit based one. A long, long time ago, I was taught to
use shellac knotting to prevent bleed-through, and the only reason I
now use Zinsser is that it is slightly paler, and can be used more
easily under one-coat paints.

John Schmitt wrote:

it is a matter of some
puzzlement to me as to why these stains can penetrate an oil-based
medium.

I don't think they can, but they do penetrate water based "stain blockers".

"Mr Fuxit" wrote in message
oups.com...
However the stain block (water based) is still showing the colour through
after two coats.

As far as I am concerned, no water based stain block can be as
efficient as a spirit based one. A long, long time ago, I was taught to
use shellac knotting to prevent bleed-through, and the only reason I
now use Zinsser is that it is slightly paler, and can be used more
easily under one-coat paints.


I've just remembered that i've got a tin of Zinsser stain block, which says
on the tin "water clear up", which presumably means it's water based.

The actual product i've got is Zinsser Bulls Eye 1-2-3, which is a
primer/stain block thingey.

"RedOnRed" wrote in message
...

"Mr Fuxit" wrote in message
oups.com...
However the stain block (water based) is still showing the colour
through
after two coats.

As far as I am concerned, no water based stain block can be as
efficient as a spirit based one. A long, long time ago, I was taught to
use shellac knotting to prevent bleed-through, and the only reason I
now use Zinsser is that it is slightly paler, and can be used more
easily under one-coat paints.



Actually, I can see your product on here...

http://www.zinsser.com/subcat.asp?CategoryID=1

It looks like they've got quite a good range of stain blockers. I'll have to
try and alternative to Screwfix's, which to be honest - hasn't blown me
away.

On Sat, 10 Sep 2005 09:17:29 +0100, Stuart Noble
wrote:

it is a matter of some puzzlement to me as to why these stains can
penetrate an oil-based medium.

I don't think they can, but they do penetrate water based "stain
blockers".

I didn't think they could either, now I know different. The Aquaseal
product was based on some organic solvent, MEK IIRC. I tend to forget the
exact details of DIY jobs after a couple of decades.

John Schmitt

--
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

"Jim Scott" wrote in message
...
Are proprietary 'Stain block' paints any better than oil-based undercoats?

First time I saw the heading I thought it said Satan block paint! Boy I
musta been tired.

NT