Stubborn paint

Removing the residue of the paint on the plaster walls.

The walls are not flat (that's 50 year old plaster for you), so both scraping and sanding takes much longer than it would otherwise. The plaster absorbs the heat from the heat gun, which means the paint is much harder to remove than it is from wood.

With the heat gun, followed by washing the green residue off the wall.

This patch (below the line, which is about 5 feet up) took about four hours.

This was after fixing the toilets yesterday, and I learned some things that might make it go faster in future: the angle of the scraper makes a huge difference for example, and the heat gun gradually gets more effective the longer it's on - it doesn't reach its highest temperature for several minutes it seems.

A (small) section of this was done with a blowtorch rather than the heat gun. (See what happens when I'm away? Walls are SET AFIRE. - S.) This is somewhat faster - the heat is more focused and direct and the paint just blisters off, but it does leave faint scorch marks on the plaster itself.

This is the opposite wall of the hallway, after about 1:45 hours with a power sander.

The sanded wall is considerably smoother, with some of the unevenness of the wall reduced. It produces a lot of dust however, even with the dust catcher attachment.

The little bit above the line, on the left near the corner, that looks green was done with the heat gun and scraper, to do a compare, that's what it looks like before washing off the green.

Given the thickness of some of the remaining paint, a thicker primer is not going to help.

Adding a surface skim of plaster would solve both the residue, the unevenness and the remaining pockmarks.