We were engaged to clean and restore 2 large marble sculptures at the LKC Medicine Toh Kian Chui Annex. Like many of such sculptures of this design they are fully exposed to the elements and have been there for a number of years. There was a lot of general surface dirt and staining of the marble as well as lots of insect related droppings.
Unfortunately for such material once they have been exposed to the elements for a long time the marble will start to deteriorate and surface dirt can easily permanently stain the marble when left in place. Once this occurs, it is largely impossible to fully remove that discolouration without removing layers of the marble itself. You can see this discolouration particular around the base of the sculpture where stains have appeared in cracks.
To bring back the "fully white look" is effectively impossible at this stage, so the focus is about removing as much surface dirt as possible and then maintaining moving forward to reduce further staining. We would recommend with such works that they should be reviewed every 6 - 12 months.
