At some stage in the fairly recent past the bronzes of the O’Connell (by John Henry Foley) and Parnell (by Augustus Saint Gaudens) Monuments had been shot blasted at high pressure with a coarse, sharp grit, leaving an overall matte texture, then coated with a coppery-orange paint and over that, a black. Both layers of coatings had weathered off in varying degrees and overall there was a layer of dirt – the toothed profile of the shot blasted surface provides a key that helps dirt to bind to the surface.
Rainwater run-off had left streaks of pale green corrosion that were etched into the surface. There was graffiti on some of the bronze, some of which had etched into the surface. One of the wreathes had been sprayed with a coppery coloured metal spray paint and there was a considerable build-up of guano on the head of O’Connell and down the face.
In the case of the O’Connell monument, metal loss at the surface due to the highly abrasive shot blast medium has exposed large areas of porosity. Porosity harbours pollutants and moisture that can become corrosion cells. The damage caused to the O’Connell and Parnell bronzes by inappropriate treatment in the past cannot be over emphasised – the surfaces have been eroded and disfigured more by the shot blasting and coatings than the effect of total neglect or atmospheric pollutants.