stopping exposed plaster from crumbling - do i need a sealer

[alexg]

just removed a small desk which was inset into an alcove,,, it has left a groove (approx 1 inch deep by 1 inch high) around the walls of the alcove...

i want to fill in the groove, but before i dig out the big pot of polyfilla, how do would i best stabilise the crumbly expose plaster... do i use some form of pva sealant to give the filler a stable key?

cheers

 

[joe-90]

Yes. A couple of coats of 4-1 PVA should do the trick.

 

[alexg]

Yes. A couple of coats of 4-1 PVA should do the trick.

thanks... thought so..

when you say 4-1, does this mean it is watered down?

cheers

 

[BigDY]

4 parts water to 1 part PVA.

 

[joe-90]

The post above is correct.
If you apply the PVA when it is too thick it simply sits on the surface that is crumbling. What you want it to do is soak into the plaster and then harden.