A friend at work has recently removed a fireplace from her dining room
revealing the original sandstone lintle. She wants to keep this as a
feature but unfortunately some of it is covered in black heat-proof
She's tried Nitromorse on a small area without much success (and is
worried about this damaging the sandstone). She's also tried a wire
brush but while this removes some paint it also greys the sandstone.
Sanding it off is also not really an option as the surface is uneven.
Has anyone any suggestions on the best way to remove the paint,
hopefully without doing too much damage to the sandstone?