Plasterboard sealer - magic ingredient?

I wondered about Wickes wooden floor primer for tiles. Three times the price of PVA. Hmmmm.

It's supposed to be steam-proof so you can use a steam stripper to take off wallpaper without damaging the plasterboard. PVA certainly wouldn't fit the bill, and it's no good under paint either.

If you're never going to paper the wall (or rather never going to strip paper from the wall), I imagine watered down matt emulsion would work, but I haven't tried it. I always skim plasterboard.

There certainly is something different about it - it smells of PVA certainly, but something else as well in there.

If you put anything in PVA it tends to have the opposite effect of adhesion. Adding meths to it turns it into a mold release agent. But you can add paint to it and get something similar. Try squares of different mixtures on a scrap of melamine.if you don't believe me.

Only the PVA will stick firmly.

Of course there must be some additives that don't do that. Caustic soda perhaps?

I'd be nrevous about emulsion - I painted a coat of el-cheapo white emulsion on a skimmed wall to seal it before papering and I've had trouble ever since with the paper lifting at the edges. Other walls done with "proper" sealer have given no problems.