Poor plastering

[MidsTW]

The area where an old L&P stud wall was had been filled by the previous owner. Looks like he went for one coat of multi. Anyway it's crap.

Rather than taking it all off I was going to chip/sand back underflush and then skim over and feather out with some multi. Do I need to put anything on like pva before skimming?

The other side of the wall is similar but it also has some bits back to brick. Shall I get some bonding and bring almost flush? Then skim too?

 

[PrenticeBoyofDerry]

Yes always prep with primer and yes bring walls to level with basecoat bonding. Do check that all other coatings are sound.

 

[MidsTW]

Cheers!

Got a bag of thistle undercoat earlier. I put a big spirit level cross both areas earlier and the plaster is about 5mm high in places. I have sanded down with some course stuff and it has actually smoothed off the old stuff quite well. I will probably need to feather it though as the walls either side won't be colinnear.

Had a practice at skimming earlier on a bit of wall. I don't have a problem getting it smooth... But I can't seem to get the correct thickness or flatness. Scrapped off and will have another try.