Plaster retarder

[Johan2218]

Hi all.
I read on a thread that there was nothing you could add to slow down the drying process, so to give more working time.
However I have seen something called "ExtraTime plaster retarder", which comes in sachets.
Does anyone have any experience with this or any other ideas please for finishing coats of plaster?
Someone suggested "Sika Mix Plus Mortar Plasticiser" which is easily available but I thought that was only for mortar. If that works without any detriment, that would be great.

Any help/advice welcomed please.

 

[Deleted member 292770]

shouldnt need it this time of year. what are you plastering?
never used it myself but extratime seems to have good feedback.
mates used it a few times ,says it’s ok.

 

[Johan2218]

Thanks for that.
It's a very weird one... done many walls and ceilings in the past with no problems. This is a ceiling with multiple finishes of various things, mainly because it has several curves they possibly have all sorts underneath to build up those areas.
I pva as normal but the suction is all over the place... and when initially laying on, no issues...but then goes off incredibly fast. No heat or anything...it was the same in another area, same old lathe and plaster base etc. Just need an extra 30-60 mins, especially due to having to work all the curves.
The remaining ceilings are bigger, so need to plan for that.
What do you think of using that mortar plasticiser?
Thanks...

 

[Deleted member 292770]

no

 

[Deleted member 292770]

given what youve said.
do 2 coats of neat pva with some sand in (which i’m not a fan of on ceilings) or 2 coats of bostik stabilising primer , which is really good stuff. will give a good key on the ceiling and 2 coats will give uniform suction control.
make sure theres a good date on your plaster and use freezing cold water .

 

[Johan2218]

Many thanks, I will definitely look at that. I have a big wall which is similar...so I suppose the preference is the neat PVA and sand? Also I presume you mean plastering sand?
Thanks again...

 

[Deleted member 292770]

the preference is bostik grit. but pva and sand will do you. and yes neat 24 hours before skimming. building sand.

 

[Deleted member 292770]

How many coats of plaster do you normally do?

 

[Johan2218]

Great advice, thanks.
Normally two or in this case three. Not including any bonding.

 

[stevethespreader]

Cream of tartar roughly half to1 tbs per bag

 

[NickB_99]

I quite like wickes bonding agent for putting on when I’ve a variety of backgrounds to skim over. Dries well with aggregate that’s not too big.
Being able to skim it dry is a help for me and allows time as it behaves uniformly.
Also find scrim tape stays put better too.

Sometimes when using just a couple of coats of pva just before can make it slide about. Maybe that’s just me.

 

[tell80]

stevethespreader Thats great. have you tried this additive? do you know what happens long term after using it?
I think why not - so i'll give it a go with a small tub of powder. If i stop posting you'll know i'm stuck to a cellar wall someplace.

 

[stevethespreader]

stevethespreader Thats great. have you tried this additive? do you know what happens long term after using it?
I think why not - so i'll give it a go with a small tub of powder. If i stop posting you'll know i'm stuck to a cellar wall someplace.

Yes i used to use it with no ill effects be careful not to use to much as it seems to make it sloppier i used to use it in live hospitals where they had the central heating on or if i had a big job im retired now but i would knock up a big gorrilla tub 2 and a half bags i think it was and sometimes i would put a couple of spoonfuls in there it has something to do with the acidity ive also known other spreads to pee in their water onsite lol but the cream of tartar definitely works

 

[Deleted member 292770]

pee is an old one , haven’t done it and doubt the customer would appreciate it.