Operation Re-decorate - Help Please

[MFLBigDog]

Hi

I have just started decorating my 1920's end terraced house.
I am a relative novice to decorating so any advice would be very welcome.

I have stripped 7 layers of wall paper off of the hallway and landing
(all put up by the previous owner) with the intention of painting the walls.
However, when I got back to the bare plaster I have found patches of a very thin, grey in colour, film like substance on the plaster, some off which has come away when I steamed of the wall paper.

I am assuming that this is a plaster sealant???
(Please confirm or enlighten me if you wish)

To get to the point.....

Do I need to scrape all of this off or can I apply new sealant over the top of the old?

 

[Robbie uk]

It could be Lincrusta glue which was a heavy duty pre-mixed glue for hanging Lincrusta. The was made of putty and was made into very heavy wallpaper which ended up being painted or grained and varnished. If it is then it will need to come off. This was used a lot at the time the house was built and around the 20's 30's 40's

 

[MFLBigDog]

Thanks Robbie...... I had a feeling that would be the case.