Anyway thanks Roger, but if you see my previous reply to Pop youll gather im
>using coving anyway, it sits on top of the layers im gluing to the ceiling,
>god help me ;o)
That "previous reply" seems to have got lost in the post :)
Leastways, it hasn't appeared on my news feed yet.
If you are referring to putting the MDF up so that you can then add the coving afterwards (so as to create a platform for the cove to sit on), then why not use good old plasterboard as the platform? That will stick to the ceiling okay with coving whadyacallit, and the coving will stick to the plasterboard.
Plasterboard is also pretty easy to work with IMHO - a lot easier than MDF!
PoP