Someone Please Help Me - Gyproc Finshing Plaster question

[EggMella]

OMG

I mix it up, start to apply it, taking reasonable care to work it into the cracks (20mm deep - 20mm wide) I'm trying to fill. By the time I've worked my way through half the mixture (of which there is very little but about 5 minutes worth of application) it's already setting.

It's setting faster than I can apply it and if I make less I'll be mixing every 5 minutes.....

Should I be using a different sort of plaster althougher, one that doesn't set in 5 - 10 minutes? or am I just a clueless numpty?

cheers
Eggers

 

[Richard C]

OMG
I mix it up, start to apply it, taking reasonable care to work it into the cracks (20mm deep - 20mm wide) I'm trying to fill. By the time I've worked my way through half the mixture (of which there is very little but about 5 minutes worth of application) it's already setting.

You say finishing plaster, if it's Multi Finish its not suitable for what you’re doing; it’s only suitable for 3-5mm thickness maximum or it will crack & most probably fall out.
What exactly are you trying to do? No plaster is suitable for filling 20mm deep cracks in one hit & if the blocks/bricks are cracked underneath, it will only crack open again.

OMG
It's setting faster than I can apply it and if I make less I'll be mixing every 5 minutes.....

It shouldn’t be going off that quick, how old is the plaster (use before date on the bag) & where have you been storing it? What type of surface are you applying it to? Are you preparing the surface properly.

OMG
Should I be using a different sort of plaster althougher, one that doesn't set in 5 - 10 minutes? or am I just a clueless numpty?

No “in date” plaster will set in 10 minutes but you may have to prepare/seal the surface first, depending on how absorbent it is, that may be your problem. You should probably be using a different plaster or even render but you need to explain what exactly you are trying to do.

 

[EggMella]

Correction the plaster is Thistle finishing plaster it's going off in the container I mix it in not just on the walls.... It's been stored, open, under the stairs for about 4 months.

Basically I've had some new windows fitted and there are some gaps between the metal (aluminium) window frame and the plaster on the walls (1930's house). I'm trying to fill the gaps between the two, this is going directly on to brickwork.

Thanks for your input so far......

cheers
Eggers

 

[Alastairreid]

the plaster has went off
time to splash out a fiver on another bag

 

[Richard C]

Correction the plaster is Thistle finishing plaster

There is no such product "Thistle finishing plaster"; it’s either Multi-Finish, Board Finish or Durafinish; but it makes no odds really.

Correction; it's not listed in their website product range but does appear to be sold in 12.5kg bags at some DIY outlets; very confusing

it's going off in the container I mix it in not just on the walls.... It's been stored, open, under the stairs for about 4 months.

Well that’s your problem; it has a definitive shelf life (printed on the bag) but once opened it’ll be fit only for the tip if not used within a few days; it can't be stored like Pollyfilla!

Basically I've had some new windows fitted and there are some gaps between the metal (aluminium) window frame and the plaster on the walls (1930's house). I'm trying to fill the gaps between the two, this is going directly on to brickwork.

Use a 1:3 mix PVA/water mix on the brickwork & let it dry overnight; then PVA again (1:5 mix ), let it go tacky & use Bonding plaster & build the area up in 2 layers of around 10mm thick, letting each go off, to approx 3mm below the surface; then fill out & finish off to the surrounding area with Multi-Finish. Do it in one session because if you let the Bonding plaster dry out, it will have to be sealed with PVA again.

 

[nick13]

Sound like the stuff is old. Throw it away and buy some fresh, from a builders merchant... one that is busy and turns around its stock fast.

Nick

 

[Richard C]

Throw it away and buy some fresh, from a builders merchant... one that is busy and turns around its stock fast.

B&Q Trade stores are one of the best places to get plaster/cement products;
• prices are very keen & usually much less than the 3 large Builders Merchant chain outlets, even if you have a trade account.
• at the price they sell the stuff, turnover is high so it’s not been sitting around for long periods.
• storage conditions are very good, much better than the average damp tin shed in a BM yard so less likely to have gone off.

 

[nick13]

Throw it away and buy some fresh, from a builders merchant... one that is busy and turns around its stock fast.

B&Q Trade stores are one of the best places to get plaster/cement products;
• prices are very keen & usually much less than the 3 large Builders Merchant chain outlets, even if you have a trade account.
• at the price they sell the stuff, turnover is high so it’s not been sitting around for long periods.
• storage conditions are very good, much better than the average damp tin shed in a BM yard so less likely to have gone off.

I agree. In addition, when you buy the stuff, use it straight away.

 

[EggMella]

Perfect.... thanks to everyone for their replies... Product originally came from B&Q and now I know that I don't need to get the stuff on the wall within 5 minutes under normal conditions I'll reattempt at the weekend