Does bonding coat need a pva skin?
Some leave it to the following day before skimming, depending on the size of the area.
It is possible to apply PVA glue immediately before the skim coat is applied.An extra coat can be applied and both allowed to dry before the re plastering of the wall.The scraper should happen before the process.
If very porus, a thin mix won't hurt, just wet the wall.
There are different types of plaster.Bonding is an undercoat plaster.Bonding does not need the wall underneath to be scratched or have a mechanical key and bonding agents, such as latex SBR adhesive, are usually applied to the walls before the bonding plaster itself.
I think the routine is to apply 1 coat of PVA and allow it to dry completely.After 24 hours, apply the second coat of PVA and then apply plaster.The second coat should be tacky.
Black mould needs water and heat to grow, water condenses from warm humid air against a cooler surface, painting will not stop it growing.Dehumidify is not the best solution because it will suck water from air outside.