1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Painting walls and ceilings nothing speical

Discussion in 'Decorating and Painting' started by HawkEye244, 8 Feb 2020.

  1. HawkEye244

    HawkEye244

    Joined:
    18 Aug 2008
    Messages:
    3,488
    Thanks Received:
    238
    Location:
    London
    Country:
    United Kingdom
    Hi all,
    Other than wash down walls and ceilings with a bit of sugar soap and then water prior to painting, do plastered surfaces benefit from a rough sand to key them ? Why is keying needed on wood but not plaster? Thanks
     
  2. opps

    opps

    Joined:
    16 Jun 2006
    Messages:
    3,879
    Thanks Received:
    563
    Location:
    London
    Country:
    United Kingdom
    I sand new plaster as a matter of course but that is to remove any imperfections. From time to tie you do come across plaster than has been "polished" too much by the plasterer. Painting over it is like painting on glass and sanding definitely helps.

    Standard matt emulsion on plaster is quite porous and accordingly additional coats of matt emulsion don't require a key.

    I must admit that i have never stopped to think about non-porous finishes such as waterbased eggshell on walls. I guess that they would benefit from a key when applied over existing wb eggshell.

    I have seen WB eggshell applied straight over OB eggshell without a key, it didn't pass the "fingernail test".
     
    • Thanks Thanks x 1
  3. Sponsored Links
  4. HawkEye244

    HawkEye244

    Joined:
    18 Aug 2008
    Messages:
    3,488
    Thanks Received:
    238
    Location:
    London
    Country:
    United Kingdom
    Good info, thanks bud!
    Want as good a finish as possible without giving myself work.
     
    • Like Like x 1
  5. sparkwright

    sparkwright

    Joined:
    20 Aug 2009
    Messages:
    7,108
    Thanks Received:
    862
    Location:
    Dorset
    Country:
    United Kingdom
    Reading that reply suggests new plaster, but reading the original post it suggests it's already painted plaster.

    I read it as painted plaster.

    In which case give it a quick rub down all over. Don't go too crazy. It will help if there is a problem. Usually emulsion can go straight over matt emulsion, but a quick rubdown will get rid of any bits in the old paint.

    Be sure to thoroughly remove any sugar soap, if you don't it may react with the paint.

    Rubbing down wood is more important usually, as new paint doesn't stick very well to glossy surfaces.
     
    • Thanks Thanks x 1
  6. Sponsored Links
Loading...

Share This Page