Drying too quick

[PhiLyn]

Guys, please help - I'm going bonkers!!!!

I'm currently skimming a few walls that we recently stripped of wallpaper leaving old plastered walls (with too many bumps and cracks to paint over).

I've PVA'd all the walls twice and yet this has not slowed down the Multi-Finsh drying time - even the smallest of walls is causing severe headaches!!!

I've checked all the obvious - the plaster has a good date on it (and doesn't dry too quickly on the table or on plasterboard) and everything I'm using is clean and free from any old plaster that may not be helping. I've even given a wall a third coat of stronger PVA/water mix (about 3 part water to 1 PVA). It's TP's own brand of PVA so should be ok.

Am I going bonkers or am I doing something fundamentally wrong (apart from not getting a pro in....)?

 

[noseall]

First question i have to ask is, you are putting more than one coat on aren't you?

 

[PhiLyn]

If you mean PVA then yes - 2 oe 3 coats.

If you mean plaster then no - I was hoping to get away with one coat but have had to resort to two because of all the problems - even the second coat went off like a rocket!!!!

 

[Richard C]

You seem to be aware of & mostly covered the angles; was it bare plaster or painted? How/when did you PVA? What's the time scale of your "rocket" ? You should be aiming to get it all up there within 40-45 minutes which will (should) easily leave you enough time to float off & finish up; if your significantly longer, you will have problems on all but the smallest of walls.

If it really is going off on you that quickly then my favourite this time of year would be it’s been badly stored. I always buy from nice, heated B&Q trade warehouse rather than a damp tin BM’s shed this time of year; it can still be well in date but if its been badly stored for a couple of weeks then it can still be a problem. You say it’s OK on the board but what’s OK, 20 mins; 40 mins; more?

 

[PhiLyn]

It's bare plaster. I PVA with a roller (with most of it going down my arm!!!) and brush for the edges. I've been waiting for it to go tacky before plastering (is this too late / too soon?)
I had trouble today with a wall that was 4 sq m - it took me about 15 minutes to get on as there was a doorway to negotiate around. By the time I'd got to the end, the plaster at the bit I'd started on was almost bone dry and VERY difficult to float off. I decided to put a second coat on top to sort out the problem and did so as soon as I could. Becasue the base coat had dried so much I had to same problem with the top coat (but not as bad as it went on a lot quicker).

I see your point about the storage of the bags, but I'd done the ceiling this morning (which was painted) and the plaster lasted a lot longer (and was from the same batch).

I've just moved on to these walls after plastering plasterboared walls upstairs. I've been coping with much bigger walls than this with no problems so I was guessing it's something to do with my PVAing. Either that or my walls are thirsty!!!

Would neat PVA on the walls maybe help?
Should I just have bought shares in Polyfilla and gone down that route?

 

[wozza56]

Does the plaster in the bag feel nice and powdery or is it more gritty with small lumps and when on the spot does it have a bit of a shine ?

 

[noseall]

If you mean PVA then yes - 2 oe 3 coats.

If you mean plaster then no - I was hoping to get away with one coat but have had to resort to two because of all the problems - even the second coat went off like a rocket!!!!

I actually meant plaster.

It is far easier to apply two moderate coats of plaster than one thick one.

The first coat is somewhat sacrificial as far as moisture is concerned it allows subsequent coats to be worked more easily.

 

[Micilin]

Are you sealing up with PVA the day before?

 

[roy c]

Did you pva it 24 hours before you started to skim it, and before you skimmed it did you pva it again and let that go tacky..The 24 hours bit is the most important part

 

[Richard C]

Skimming plaster board is a doddle, that’s what it was designed for after all. Painted surfaces have virtually no suction so will not present any real problems & can even give you more time than PB but you must prep them (what you do depends on the paint) & PVA prime them or the plaster won’t adhere very well.

As others have already said; on bare, dried plaster you must seal or you will have real problems with suction. Don’t use neat PVA; a couple of quick coats of 1:2/3 but you must leave it 24 hours. PVA again with a couple of quick coats of 1:4 ish; I use a roller for this bit but if you use a brush don’t keep on at it or you’ll create more problems; skim when tacky.

I’m still unsure about how much time you’re taking & you may just be running out of it. Taking 15 minutes to lay on 4 sq/m is far too long, it should be more like 8-10 sq/m! The times I gave are what I would normally expect of a good mix on an ideal surface in ideal conditions (not too hot); it won’t get any better than that but can certainly get a lot worse if the prep is not good, it’s hot or your plaster is crap.

 

[PhiLyn]

Thanks guys - will have another go at it tomorrow.

 

[tommyl18]

another point to make is make sure uve got no draft coming through where ur plastering make sure windows and outside doors etc are shut because if u get a wind blowing on ya work it will go off like a good en!!

 

[neds]

Taking 15 minutes to lay on 4 sq/m is far too long, it should be more like 8-10 sq/m!

wow thats something I'd lilke to achieve but I'm far from that yet!

 

[tommyl18]

youve got to get it on as fast as you can once its on u can then take ya time to trowel it down if u take ya time putting it on ull be working ya nuts off then to trowel it down and have right arm ache haha!!

 

[GotWood]

Quick question if I may: Given the 24hrs PVA advice, should I be worried if I get a plasterer in and he starts plastering on the same morning? I too need old bare plaster skimmed.

Thanks.