Plaster basement wall

[andi_j]

I know this has come up before, but I just want a quick, concrete answer.
I have a basement wall that is currently uneven and painted with plastic paint; I want to plaster it and even it out.
Can I do this without removing the paint by using some miracle primer/plaster or something similar? I would also prefer to use plaster since I don't want to add too much material.

André

 

[anaitis]

Remove the paint!
Is it an inner wall or outer wall?
Below ground or above?

 

[andi_j]

apparently missed important information:
the wall is mostly underground on the inside.
do I really need to remove the paint, the rest of the basement is dry.

 

[b8q]

I would remove the plastic paint if I were you, at least on the lower half of the wall. If/when your drainage gets worse, the moisture will creep...

 

[andi_j]

is it sanding with that kind of concrete giraffe that's the way to go then? or another sander for that matter, or can you heat and scrape?

 

[mrVoodoo]

Sanding off plastic paint on plaster sounds very tricky to me. Sure, you can sand paint with a "regular" sander, but as soon as you go through the paint, the plaster will ruin the sandpaper. Then it would be a concrete sander, but I almost think it would clog up instead due to the plastic paint. Now I'm mostly speculating since I haven't tried it myself, maybe someone who has tried can fill in with some more facts.

If I were doing it myself, I would probably try with a concrete sander first to see if it works. If that doesn't work, I would probably consider chipping away the plaster if it isn't rock-hard; with a wide chisel and a decent demolition hammer, it goes fairly quickly on slightly older plaster.

Regarding a concrete giraffe, I've never seen/heard of such a thing? o.O

 

[puu]

No primer will help as the weak link will be between the paint and the old plaster.
When I tiled in my basement, I just scratched off the plastic paint, those who live will see if it holds but I'm not worried. I drained the year before.

 

[LasseR]

Sanding off plastic paint on plaster sounds very tricky to me. Sure, you can sand paint with a "regular" sander, but as soon as you go through the paint, the plaster will ruin the sandpaper. Then it would have to be a concrete sander, but I almost think it would instead get clogged by the plastic paint. Now I'm mostly speculating since I haven't tried it myself, maybe someone who has tried can fill in with a bit more facts.

If I were doing it myself, I would probably try with a concrete sander first to see if it works. If that doesn't work, I would consider chiseling away the plaster if it's not rock hard; with a wide chisel and a decent demolition hammer, it goes fairly quickly on slightly older plaster.

Regarding a concrete giraffe, I've never seen/heard of one of those? o.O

I have a concrete sander (Bosch GBR 14) and for it, there are diamond cup wheels specifically designed to remove paint on concrete surfaces (the wheel is called SPP). It might be a good idea to rent/borrow such a machine as the removal goes quite quickly.

/Lasse

 

[andi_j]

yes, it will probably involve using a concrete grinder, used one of those to grind off asphalt from a wall before.