pva mess
- Thread starter brist
- Start date
Richard C said:
I find rollering it on is useless personally. Doesn't get a decent enough coat of PVA on. I've been caught out twice now and have stopped rollering it on because you either need to put four coats on to get decent coverage or not out enough on and cope with the consequences when spreading.
I do know what you mean though Brist, the stuff gets everywhere and if you've got short sleeves on it even gets caught in your underarm hair!!! I find it's best to apply with a brush, taking your time and not overloading the brush. Dipping frequently and applying to a small area at a time.
Obviously, in a room where a complete refurb is being done and mess isn't an issue I just throw the stuff everywhere. Fill the brish and slap it on but the mess is awful!
This makes me wonder if you have any idea why you're using PVA.FredFlintstone said:
The idea isn't to "coat" the surface, but to provide the right amount, in the right dilution, of PVA for it to soak into the surface. If just sits on top it achieves nothing. Actually, it probably does achieve something, which is to introduce something that might, depending on the chemical make-up of the PVA you're using, become solution again when you apply whatever thing you're applying to the ceiling, but I presume you want that thing to stay there instead of flake off.
Softus said:
No, you've mis-understood me I think. What I'm saying is that when applied by roller, not enough PVA is applied to the surface in order to be effective. I've found, in my experience, that applying by brush is far more effective and therefore, I prefer using a brush.
I don't understand why me mentioning coating the surface suggests that I don't understand the principle behind PVA and its use to control suction and create a bond between porous surfaces.
Methinks you may be being just a wee bit pedantic and trying to read too much into something that isn't.
If so, then I apologise. I've been wrong before, and I'll be wrong again. No offence was intended. Have a nice BHM (if your weather is better than I'm suffering).FredFlintstone said:
I agree. I think the problem with PVA is that it isn't paint, and therefore contains none of the additives (that we take for granted these days) to stop it dripping either off the brush or down the wall.
OK. I accept that you don't understand.
Pedantic? Yes.
However, hopefully I haven't entirely wasted your time and mine, because someone else reading the topic may have learned something that you and I already knew.
If you arems are up to it, use a brush and hold ya PVA bucket just underneath it.
Youll still get it down ya arms but it reduces how much goes elsewhere.
And get plenty of waterproof dust sheets!
Just some tips from a learner, and i aint pretending to have been in the game for years!
When you say that its to create a bond etc, does that mean you shouldnt let one coat of PVA go sticky? Surely that would make it more of a seal?
Dunno?
Youll still get it down ya arms but it reduces how much goes elsewhere.
And get plenty of waterproof dust sheets!
Just some tips from a learner, and i aint pretending to have been in the game for years!
When you say that its to create a bond etc, does that mean you shouldnt let one coat of PVA go sticky? Surely that would make it more of a seal?
Dunno?
Yes, let one coat go tacky. First application is quite weak and primes the surface, second a bit stronger. If you're applying to a porous surface it won't seal the surface completely, it will simply reduce the porosity thus stopping the porous surface sucking all the water out of your plaster as soon as it touches the wall.
Even if the PVA does seal the wall completely, because the PVA itself has absorbed into the porous surface it will have created a strong bond to the surface so isn't likely to peel off, taking your skim coat with it.
I have skimmed a non porous surface before now, first using two coats of neat PVA and the skim did bond OK but it just slid about all over the place when I was laying it on and took ages to go off. It wasn't easy to finish but I got there in the end.
Regards
Fred
Even if the PVA does seal the wall completely, because the PVA itself has absorbed into the porous surface it will have created a strong bond to the surface so isn't likely to peel off, taking your skim coat with it.
I have skimmed a non porous surface before now, first using two coats of neat PVA and the skim did bond OK but it just slid about all over the place when I was laying it on and took ages to go off. It wasn't easy to finish but I got there in the end.
Regards
Fred