Help! New plaster ceilings and Primer ON paint?

[drarwood]

Hi,

We've recently had our ceilings replastered. We were told that we should do a thin coat of watered down emulsion prior to adding coats of normal emulsion on top. But we are not getting the best results as some places look patchy even after a third coat of Matt emulsion.

Some people say you can you use a primer on plaster but as we've already painted on it I just wondered whether we could still do this?

Any advice greatly appreciated.

Thanks