Plastering over Paint?

Hello, can anyone help with the following?........

We have ripped all the tiles off in our bathroom, and in some patches the tile adhesive has taken off a couple of mm of lathe. I want to just skim these patches rather than redoing the whole wall - so do i have to seal the lathe which is now exposed before plastering, and generally speaking, will replastering small patches like this look nice and smooth, or look....well, patchy?

Also if i have done the above and painted it - and then decided it does look too patchy and bumpy - can I plaster over the top of the paint (or how do i prepare it?).

Any advice would be really appreciated.

Many Thanks

James

To plaster over paint you should make up a mix of 50:50 PVA Adhesive and Water, paint that over the paint, let that dry and then mix 75:25 PVA and water then paint that over the previous coat of PVA.

This should prepare the wall for plastering.

As for the lathe, you maybe able to get away with patching it. What do you have to loose.

Marc

Thanks for the advice on preparing paint to be plastered. I have had a go at just doing the patches, and the result is pretty good, so hopefully i might avoid doing the whole wall. Im sure it'll come in handy for the future though.
Thanks Again