PROBLEMS with Water-Based Paint for Wood
Interloper
etc. to paint, and I don't much enjoy painting.
It seems that 'elf 'n' safety and environmental concerns have encouraged
most manufacturers to change to water-based paints. After much
deliberation, I purchased some Ronseal KnotBlock Wood Primer & Undercoat,
and some Ronseal Diamond Hard Wood Paint in Pure Brilliant White Satin.
I started applying the Ronseal primer/undercoat using the recommended
synthetic brush. The paint dragged and was very difficult to brush out
smooth. I was painting bare pine. I asked Ronseal whether I could thin the
paint for the first coat. They said I could thin the paint with up to 10%
cold water (although thinning the paint isn't mentioned on the tin, or on
Ronseal's website). The thinned paint was a bit easier to apply, but it was
still hard work.
I encountered several problems:
1. The paint dries quickly - much too quickly - on the brush. The drying
paint causes the shorter, outer bristles of the synthetic brush to twist &
curl, making the brush look like it's having a bad hair day. Washing the
brush out in water every 15-30 minutes seems to be the only way of resolving
this.
2. The drying paint quickly causes the brush bristles to clump together.
This makes it very difficult to paint curves or mouldings because instead of
the bristles fanning out evenly over the contour, the brush simply splits
into two or three clumps, thereby missing much of the surface. Again,
washing the brush out in water every 15-20 minutes seems to be the only way
of resolving this.
3. I keep getting tiny lumps in the paint. At first I thought these lumps
were actually in the paint. Now I think they are small pieces of
partially-dried/hardened paint dropping off the brush bristles, even though
I wash the brush clean every 15-20 minutes. I have resorted to lightly
rubbing down the paint between coats to remove these lumps.
The cause of these problems appears to be that the paint starts to harden
within the brush bristles very quickly and the process of adding more paint
to the brush as the painting proceeds does not stop this hardening process.
I never experienced any of these problems with spirit-based paints.
Maybe I need to change my technique, or maybe this is as good as it gets
with modern, environmentally-friendly, water-based paints - I don't know.
I would welcome any advice or comments before I become totally pi$$ed off
and abandon the project.
Maybe someone could recommend a better make/type of paint for wood that does
go on smoothly and doesn't require the brush to be washed out every few
minutes (a friend has suggested Dulux Trade paints)?
Thanks
--
Interloper
Skipweasel
says...
> Maybe someone could recommend a better make/type of paint for wood that does
> go on smoothly and doesn't require the brush to be washed out every few
> minutes (a friend has suggested Dulux Trade paints)?
I rather like Wilkinson's water-based silk paint. Used with a small
short-pile roller it made a smashing job of radiators and panelled
doors.
--
Skipweasel - never knowingly understood.
stephe...@btinternet.com
"Interloper" <intr...@gmail.com> wrote:
>I have a whole load of pine skirting, doorframes, window cills, pelmets,
>etc. to paint, and I don't much enjoy painting.
>
>It seems that 'elf 'n' safety and environmental concerns have encouraged
>most manufacturers to change to water-based paints. After much
>deliberation, I purchased some Ronseal KnotBlock Wood Primer & Undercoat,
>and some Ronseal Diamond Hard Wood Paint in Pure Brilliant White Satin.
>
It sounds to me that the wood is a bit too porous and is absorbing all
the water solvent, perhaps an even thinner application would suffice and
apply more that one coat, the first coat applied very thin just to seal
the wood, then try the second coat when the first is thoroughly dry.
This particular water based wood primer is supposed to dry in about six
hours, not six minutes.
Stephen.
--
http://www.stephen.hull.btinternet.co.uk
From the Wirral Peninsular.
Coach painting tips and techniques + Land Rover colour codes
"Whatever is rightly done, however humble, is noble". Henry Royce
Roger Mills
> I have a whole load of pine skirting, doorframes, window cills, pelmets,
> etc. to paint, and I don't much enjoy painting.
>
> It seems that 'elf 'n' safety and environmental concerns have encouraged
> most manufacturers to change to water-based paints. After much
I always use International brand primer/undercoat - applied with a
'proper' brush - and don't have the problems described above. Water
based gloss is also fine for doors and skirting boards. Don't use it on
internal window sills on which plant pots etc. will be stood - the paint
discolours under the pots. It's also no use on MDF surfaces which may
get wet - kitchen window sills, etc. - water causes little pimples to
appear on the surface. You can still get oil-based external grade gloss
if you shop around.
--
Cheers,
Roger
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harry
This water based stuff is crap as you have discovered.
The next thing you will discover is that the slightest knock fetches
it off.
I have a cunning stock of real paint.
docholliday
>
> - Show quoted text -
The problem I found with water based primer was that it raised the
grain, so that the surface the joiner had just spent time sanding was
now a series of ridges and furrows. Fine if you want that, but it
wasn't the effect I'd hoped for. It wasn't really unexpected - that
was why I'd told the painter to use an oil based primer - but of
course the chap doing the job thought he knew better...
--
Mike
stephe...@btinternet.com
docholliday <dochol...@gmail.com> wrote:
>On Mar 7, 8:56 am, harry <haroldhr...@aol.com> wrote:
>> On Mar 6, 10:03 pm, "Interloper" <intru...@gmail.com> wrote:
>>
>> > I have a whole load of pine skirting, doorframes, window cills, pelmets,
>> > etc. to paint, and I don't much enjoy painting.
>>
>> This water based stuff is crap as you have discovered.
>> The next thing you will discover is that the slightest knock fetches
>> it off.
>> I have a cunning stock of real paint.- Hide quoted text -
>>
>> - Show quoted text -
>
>The problem I found with water based primer was that it raised the
>grain, so that the surface the joiner had just spent time sanding was
>now a series of ridges and furrows. Fine if you want that, but it
>wasn't the effect I'd hoped for. It wasn't really unexpected - that
>was why I'd told the painter to use an oil based primer - but of
>course the chap doing the job thought he knew better...
>
>--
>
>Mike
I wonder what they use as a thickener/medium in these water based paints
other than the pigmment? Usually with an oil base the oil itself is
generally thick enough to create the coverage without being absorbed too
much.
The Natural Philosopher
below, and also provides a good base for the pigmented undercoat that
goes above.Water based primers are thick and fast drying and that's
fine, you simply need to sand the thing smooth before the undercoat goes
on, using (probably wet) and dry paper, wet.
stephe...@btinternet.com
>goes above. Water based primers are thick and fast drying and that's
>fine, you simply need to sand the thing smooth before the undercoat
>goes on, using (probably wet) and dry paper, wet.
>
If water based primers are thick and fast drying what do they use as a
thickener?
In my experience the water based primers I've used have always been
quite thin, again as opposed to an oil.
I know primers and undercoats contain more solids and less solvent/oil
to provide the coverage, whereas the water based types appear to lack
even more in pigment.
Flatting down between coats is normal practice anyway whether its done
wet-or-dry but more heavier flatting will be necessary if the grain has
been raised too much especially if you want to achieve a finer finish.
Obviously the more solvent it contains the more it will soak in but
there has to be a compromise on how much will soak in and how fast it
dries.
This Ronseal primer mentioned appears to be drying too fast which would
normally give less time for the solvent to absorb into the wood, but if
the wood is particularly porous then it will soak up solvents like a
sponge which is what I'm guessing is happening to the OP.
Interloper
I spoke to Ronseal Technical today and they are replacing the paint so I can
try a different (fresh) batch to see if the problems persist. They are also
taking my old paint back to see if there is anything wrong with it.
Personally I think the problem is that the water-based paint rises up inside
the brush bristles by capillary action and immediately starts to harden.
This quickly causes the brush to stiffen and the bristles to clump together,
rendering the brush inflexible and ineffective. Regularly and frequently
washing the brush out seems to be the only viable workaround. Maybe
employing two synthetic brushes, one in use, the other soaking in water, and
swapping them every 15 minutes or so is the answer. It's a lot of faffing
around!
Water-based paints seem much more difficult to apply and brush out smoothly
than traditional spirit-based paints. Another 'wart on the arse of
progress', as my work colleague is often heard to say.
I'll report back after I have tried the replacement paint.
--
Interloper
stuart noble
>if
> the wood is particularly porous then it will soak up solvents like a
> sponge which is what I'm guessing is happening to the OP.
>
This is the problem with all surface coatings, solvent or water based.
In an ideal world none of the solvent gets absorbed into the substrate
and the film forms in ideal conditions (glass is often used to test
paint films).
Acrylic resins require a minimum film forming temperature (MFFT), below
which they just craze into a white powder. At one end of the scale you
have a resin that will cure at anything above freezing but has the
properties of cling film. Those that are as hard as perspex require
upwards of 20 degC, so can only be applied in a controlled environment.
Coalescing solvents can lower the MFFT but only at the expense of drying
time, so it's easy to see why most water based systems for domestic use
are something of a dog's dinner.
harry
ie Crap.
stephe...@btinternet.com
stuart noble <stuart...@ntlworld.com> wrote:
It would be better to seal the bare wood with shellac first to stop the
absorption rate, then apply primer etc.
I want to paint my internal doors and woodwork with a more none
yellowing paint than a synthetic gloss, even the expensive white
gloss paints still go yellow after a couple of years.
The only way I can see of achieving this is by using a water based type
of acrylic or even a vinyl silk emulsion but none of these types of
paint can live up to the application of an oil.
stuart noble
IME the white acrylic primers work pretty well on most surfaces, it's
the satin/gloss topcoats that are crappy (although they are 100%
non-yellowing). To get the twin properties of hard wearing and
non-yellowing you need specialist solvent based polyurethanes, which are
mighty expensive and not easy to find.
My compromise would be 2-3 coats of primer/undercoat sanded smooth
followed by the thinnest possible coat of gloss
docholliday
wrote:
> stephen.h...@btinternet.com wrote:
> > In message <61af30cd-7588-47d2-bc39-311ef1af4...@o10g2000vbg.googlegroups.com>
My experience has been that by the time you have the surface smoothed
again all the parts which were raised by the water based primer are
now completely bare again, so needing another coat of primer...
stephe...@btinternet.com
stuart noble <stuart...@ntlworld.com> wrote:
PVA would work but it may raise the grain more as its water based and
will take longer to dry than shellac which is almost instant drying
which is why it was used on bare wood for coach work.
>To get the twin properties of hard wearing and non-yellowing you need
>specialist solvent based polyurethanes, which are mighty expensive and
>not easy to find. My compromise would be 2-3 coats of primer/undercoat
>sanded smooth followed by the thinnest possible coat of gloss
My internal doors (which are new) I have already painted in white
emulsion the architraves and skirting are still in gloss, I intend to
repaint over the gloss with an emulsion type finish to avoid the
yellowing you get with an oil.
Unfortunately a thin coat of gloss will still yellow.
stephe...@btinternet.com
docholliday <dochol...@gmail.com> wrote:
>On Mar 7, 7:24 pm, The Natural Philosopher <t...@invalid.invalid>
>wrote:
>> stephen.h...@btinternet.com wrote:
>> > In message <61af30cd-7588-47d2-bc39-311ef1af4...@o10g2000vbg.
>> > googlegroups.com> docholliday <dochollida...@gmail.com>
>> > wrote:
>>
>> >> On Mar 7, 8:56 am, harry <haroldhr...@aol.com> wrote:
>> >>> On Mar 6, 10:03 pm, "Interloper" <intru...@gmail.com> wrote:
>>
>> >>>> I have a whole load of pine skirting, doorframes, window cills, pelmets,
>> >>>> etc. to paint, and I don't much enjoy painting.
>> >>> This water based stuff is crap as you have discovered.
>> >>> The next thing you will discover is that the slightest knock fetches
>> >>> it off.
>> >>> I have a cunning stock of real paint.- Hide quoted text -
>>
>> Primer is very much something that fills the grain, and keys to the wood
>> below, and also provides a good base for the pigmented undercoat that
>> goes above.Water based primers are thick and fast drying and that's
>> fine, you simply need to sand the thing smooth before the undercoat goes
>> on, using (probably wet) and dry paper, wet.-
>My experience has been that by the time you have the surface smoothed
>again all the parts which were raised by the water based primer are
>now completely bare again, so needing another coat of primer...
Using a water base primer sort of defeats the object, at least with a
good coat of oil primer you can flat without worrying too much about
rub-through, although its the undercoat which is supposed to be wet
flatted after you have built it up, but we can't seem to find a suitable
water based primer that has the same body as an oil to build up with.
The Natural Philosopher
I have used up to 15 coats of primer rubbed back to the wood to get
perfect 'plastic' finishes on wood..frankly if all you want is a
covering coat that lets the grain show through, why not let the brush
strokes show through?
Water based primer actually worked pretty well for me. The under and top
coats were oil, tho :-)
> Stephen.
>
>
docholliday
> In message <ca541169-f711-4236-bc36-cdc0d3f0d...@w6g2000vbo.googlegroups.com>
> docholliday <dochollida...@gmail.com> wrote:
>
>
>
>
>
> >On Mar 7, 7:24 pm, The Natural Philosopher <t...@invalid.invalid>
> >wrote:
> >> stephen.h...@btinternet.com wrote:
> >> > In message <61af30cd-7588-47d2-bc39-311ef1af4...@o10g2000vbg.
> >> > googlegroups.com> docholliday <dochollida...@gmail.com>
> >> > wrote:
>
> >> Primer is very much something that fills the grain, and keys to the wood
> >> below, and also provides a good base for the pigmented undercoat that
> >> goes above.Water based primers are thick and fast drying and that's
> >> fine, you simply need to sand the thing smooth before the undercoat goes
> >> on, using (probably wet) and dry paper, wet.-
> >My experience has been that by the time you have the surface smoothed
> >again all the parts which were raised by the water based primer are
> >now completely bare again, so needing another coat of primer...
>
> Using a water base primer sort of defeats the object, at least with a
> good coat of oil primer you can flat without worrying too much about
> rub-through, although its the undercoat which is supposed to be wet
> flatted after you have built it up, but we can't seem to find a suitable
> water based primer that has the same body as an oil to build up with.
>
> Stephen.
>
based primer I'd specified, which allowed me to put on the rest of the
coats with just flatting the undercoat. That's why I was annoyed that
the person supplying the door for me to fit had used the water based
primer instead of oil based - if I'd known he only had water based
primer available I'd have told him to supply it unprimed.
Mike
stephe...@btinternet.com
The Natural Philosopher <t...@invalid.invalid> wrote:
>stephe...@btinternet.com wrote:
>> In message <ca541169-f711-4236...@w6g2000vbo.googlegroups.com>
>> docholliday <dochol...@gmail.com> wrote:
>>
>>> On Mar 7, 7:24 pm, The Natural Philosopher <t...@invalid.invalid>
>>> wrote:
>>>> stephen.h...@btinternet.com wrote:
>>>>> In message <61af30cd-7588-47d2-bc39-311ef1af4...@o10g2000vbg.
[snip]
>>> My experience has been that by the time you have the surface smoothed
>>> again all the parts which were raised by the water based primer are
>>> now completely bare again, so needing another coat of primer...
>>
>> Using a water base primer sort of defeats the object, at least with a
>> good coat of oil primer you can flat without worrying too much about
>> rub-through, although its the undercoat which is supposed to be wet
>> flatted after you have built it up, but we can't seem to find a suitable
>> water based primer that has the same body as an oil to build up with.
>>
>
>I have used up to 15 coats of primer rubbed back to the wood to get
>perfect 'plastic' finishes on wood..frankly if all you want is a
>covering coat that lets the grain show through, why not let the brush
>strokes show through?
15 layers seem pretty excessive though just to build up with, you could
half that with oil primer, but of course you have to wait longer for it
to dry, I can't see carriage or coach builders using water based crap.
I have/want absolutely no brush-marks showing on any of my paintwork,
(well I would wouldn't I). The finish I have at present on the new doors
is ideal because it has the grain effect look as a finish, I just want
them all to remain white when I paint them, however the other gloss
paintwork is like glass but that is all done in oil paint, water base is
horrible.
>Water based primer actually worked pretty well for me. The under and top
>coats were oil, tho :-)
>
You can get a good finish with vinyl silk emulsion which is a compromise
between staying white and being easy to wipe clean, but you have to work
much faster an use the right brush, but for application and ease of use
you can't beat an oil base.
stephe...@btinternet.com
docholliday <dochol...@gmail.com> wrote:
You can build up fantastic layer/s in oil, I've yet to be impressed
with any water base primer.
stuart noble
> Unfortunately a thin coat of gloss will still yellow.
>
stephe...@btinternet.com
stuart noble <stuart...@ntlworld.com> wrote:
>
>> Unfortunately a thin coat of gloss will still yellow.
>>
>A thin coat of acrylic gloss won't though
I might have a go at the Leyland acrylux gloss.
Stephen,