We have a wall that has not been looked after at all. Rising damp caused peeling. Other places just peeled anyway. It probably wasn't repainted in at least a decade or more, maybe 2 decades.
So, we scrubbed and scraped it down with a wire brush and putty knife to remove loose and flaky paint. We will probably need to spray with a pressure sprayer too.
Not all the paint comes off or will. So we are left with areas that are still painted, areas that are bare plaster and areas that are a mix.
In addition, the plaster is mostly sand and is very friable.
What is the best option to penetrate and 'save' the plaster but to also overcoat where the paint still adheres?
I thought bonding liquid but apparently that will not penetrate well and really only bonds the top particles to each other but not to the layers below. Will plaster primer be ok over old paint like that? That should penetrate better I think especially if I thin it. Do I use water-based primer or solvent based?
Any other options?