On 24 May 2007 09:56:57 -0700, Klein-4 wrote:

On May 24, 11:11 am, "EXT" wrote:
A mild acid may release the remaining plaster. Are you sure it is plaster
and not drywall compound? If it is drywall compound you may just need more
scrubbing, I don't think the acid will help much. Whatever it is, you will
have to repaint the floor, as all the scrubbing will have changed the
texture and any materials in the pores of the concrete may never come out.


I recommend scrubbing with a loaded paintbrush...