re skim or dry wall sander?

[eachpeachbarebum]

I recently posted for help with my decorating -nightmare- project and got helpful advice. Thank you and to pigletjohn the fine plaster was Ok to use!
my current problem is flaking paint on bare plaster.i know this is can be caused by not diluting paint down but my question is how should I deal with it?
I did a shoddy job on the box room and want to do better for dcs' rooms. I thought about skimming but it's not all over and I want to avoid expense if possible. I have tried sanding by hand but it's not making any impact especially on the ceilings which are the worst bits.
Please somebody say that hiring a sander will sort it?

I thought mine was quite bad, and I did it by hand (although it took a long time). Do you have coarse sandpaper? Mine was P60.

Thanks allduffedup.yes I have been using per too but guess I find it hard to know when you've done enough ifyswim bits that looked stable have since flaked under new paint.
has yours been Ok with painting? very impressed that you did it all by hand. I find it makes my arthritis worse (in fingers) so not sure I can face 2 more rooms without a shortcut/easier option!

It has been fine so far, but has only been painted for about 2 months. I did put some plaster primer on the bare bits after the sanding, although I don't know if that makes any difference.

It was a huge pain doing the sanding. Everytime I thought I'd got it smooth, I would see another bit flaking off and would have to keep going. I think hiring a proper sander is not a bad idea, you can probably get them from HSS.

If it makes you feel better, in a different room, I had to scrub all the walls by hand with a scourer to remove the wallpaper adhesive that was still stuck on after removing the wallpaper. I also had to score all the wallpaper edges around the coving and window as the wallpaper went underneath them!

Decorating eh? People always wonder why it takes me so long to paint a room, but it's prepping the walls that takes ages, not the painting!

You probably need to size the walls, by using a solution of 50% cheap white paint, and 50% water, to act as a kind of base.

PS sand it back first