Glue and skim

[Launchbury]

I leart how to skim many years ago and haven't done much for years. Today I skimmed the ceiling (over boards) in our box room.

I managed to get 2 coats on the ceiling and I'm pleased with it, I wanted to skim one of the walls at the same time; got the first coat on okay but ran out of time and couldn't get the 2nd coat on (I was blowing out of my backside).

1/. How long do I have to wait until I can go back to that wall and finish off?
2/. Do I PVA it, let it dry, PVA again and skim when tacky?

Many thanks.

 

[trowelmonkey1]

you're gonna have to PVA it to seal it and leave it until then next day before applying a 3:1 tack coat of PVA prior to skimming it.

good luck!

 

[Launchbury]

As the 1st coat only went on today is it okay to glue tomorrow and then skim the next day?

 

[IanAnderson]

You could finish it all tomorrow in my book.

 

[trowelmonkey1]

yeah be fine mate

 

[noseall]

Once skimming is mixed it goes through phases of drying which are quite predictable.

I describe plaster when first mixed as 'solid pink'.

Once on the wall and is drying, it starts to darken and lose its solid pink colour, until the whole wall is 'dark pink' or wet looking.

Next it all starts to dry out and become 'pale pink'.

One of the obvious characteristics between solid pink and pale pink stages is the ability of the plaster to take on water. In its solid pink state it is giving out moisture, but in its pale pink state it will readily take on water and is quite porous.

This change occurs just as it is turning from solid pink to dark pink.

In my opinion the plaster is no longer workable nor will it 'bind' with another coat of skim at this stage. Any subsequent coats, after the skim has gone dark, will sit on top of the first coat as opposed to keying with it as it would with solid pink material.

It is at this stage, just as it is becoming both hard and porous that pva or a keying solution is needed.

If anyone understands the above give yourself a pat on the back.

 

[IanAnderson]

What was the middle bit again.....