Plaster still soft and tacky after 24 hours

[bengasman]

Got on site today to hang a boiler on a newly platered wall, but when I checked, the plaster hadn't cured fully and felt tacky.
The plasterer insisted that he had finished it about 24 hours ago, and that it was due to rainy whether.
It looked like the normal reddish bonding stuff, which I have used myself often enough but never needed 24 hours.
Is he talking bollokz or can it really take this long? I wasn't best pleased as I couldn't work and had nothing else booked for the day since I expected to be there until evening.

 

[joe-90]

Plaster sets by chemical reaction - not drying.

 

[Richard C]

Not sure what you mean by “tacky” but it should certainly be set if not a little damp after 24 hours. No idea what he’s used but “rainy weather” will not stop plaster setting (even one coat), it will just take longer to dry out, was it just a skim coat or base coat/render & skim over block? Your description of “reddish bonding stuff” doesn’t really mean anything as there are at least two conflicting descriptions in there but if it was conventional skim then it should have been fine for you to fix to as long as you take care.

 

[joe-90]

Maybe it was that purplish stuff that comes ready mixed in a bucket. That stays tacky until it dries.

 

[bengasman]

Not sure what you mean by “tacky”

Just that, tacky, sticky, like paint was slapped on an hour ago, not just wet. I suspect he has either mixed pva in, or sprayed over it after it was plastered.

but it should certainly be set if not a little damp after 24 hours. No idea what he’s used but “rainy weather” will not stop plaster setting (even one coat), it will just take longer to dry out, was it just a skim coat or base coat/render & skim over block? Your description of “reddish bonding stuff” doesn’t really mean anything as there are at least two conflicting descriptions in there but if it was conventional skim then it should have been fine for you to fix to as long as you take care.

It looked like the stuf that is actually called "bonding" ( purple letters on the bags? ) I think. The type you use directly on brick to level it out, upto 25 mm per coat iirc.
It is in a kitchen extension of victorian house. From what I saw before, the whole thickness can be anywhere between 10 and 40 mm in total.

 

[Richard C]

I suspect he has either mixed pva in, or sprayed over it after it was plastered.

What does the finish look like; decent, dull, polished? Only a complete cretin would mix up with PVA or spray it over after. PVA might make it feel tacky if the plaster is still damp but it would not stop it setting; as joe said, plaster is chemical cure. If he’s PVA’d it, I wouldn’t like to be the Dec whose going to paint it!

It looked like the stuf that is actually called "bonding" ( purple letters on the bags? ) I think. The type you use directly on brick to level it out, upto 25 mm per coat iirc. It is in a kitchen extension of victorian house. From what I saw before, the whole thickness can be anywhere between 10 and 40 mm in total.

Bonding & others plasters can be either grey or pink depending on where the Gypsum was mined. Bonding + finish can go up to 25mm & you can push that a little locally but it’s unusual; 40mm is a joke & that needs render. If it’s that thick do you know over how long a period it was laid up to finish? If he’s laid up 40mm in two days & you walked in, that may well account for the problems as there is no way it would be dried out but it should still set. If he’s laid it all up that quick, I fear the it won’t last than long anyway!

 

[joe-90]

Sounds to me like his mix was going off in his bucket so he's stirred it up. Then to make it set he's added PVA.

 

[bengasman]

What does the finish look like; decent, dull, polished?

Looked ok to me, fairly smooth and kind of shiny. But then again, I'm a plumber not a plasterer.

Bonding & others plasters can be either grey or pink depending on where the Gypsum was mined. Bonding + finish can go up to 25mm & you can push that a little locally but it’s unusual; 40mm is a joke & that needs render. If it’s that thick do you know over how long a period it was laid up to finish? If he’s laid up 40mm in two days & you walked in, that may well account for the problems as there is no way it would be dried out but it should still set. If he’s laid it all up that quick, I fear the it won’t last than long anyway!

I've got no idea when it was done, how many coats, and how thick it actually is in total, that is why I gave my estimate of upto 40 mm.
Only sure of two things: it definitely was tacky and it was not hard. It was the tacky part that lead me to the pva idea.
I don't know, may be that is how they do it in Poland.

 

[Richard C]

I don't know, may be that is how they do it in Poland.

Ahha

 

[joe-90]

I don't know, may be that is how they do it in Poland.

Say no more. Yet another Polish chancer.

 

[bengasman]

I don't know, may be that is how they do it in Poland.

Ahha

Nothing agains foreigners of course, but that is whay I thought.

 

[Micilin]

Grab a history book lads - If it wasn't for the Polish you wouldn't have a country . Maybe visit the Polish War Memorial, or talk to a few WWII vets while you still have a chance.

Plenty of home grown cowboys to have a go at before you look for lazy stereotypes

Chances are if it's still tacky after 24 hours it's been killed by overtrowelling and/or over mixing

 

[joe-90]

Grab a history book lads - If it wasn't for the Polish you wouldn't have a country . Maybe visit the Polish War Memorial, or talk to a few WWII vets while you still have a chance.

Plenty of home grown cowboys to have a go at before you look for lazy stereotypes

Chances are if it's still tacky after 24 hours it's been killed by overtrowelling and/or over mixing

There's nothing wrong with Poles that are trained and talented. It's the Polish chancers that come over here pretending to be tradesmen just to make a fast buck that we don't like.