The fish scales in the Nash Staircase have for the last few months been undergoing a careful cleaning and repair regime. There are 11,550 of them in total, each being applied individually and with great accuracy. They are arranged in 42 rows graded from a width of 23/4 inches at the bottom to 13/8 at the top, with 275 scales in each row.
The cleaning of the scales has made a huge difference and shown how dirty all these inaccessible surfaces have become. The scales were carefully cleaned using de-ionised water and cotton wool swabs.
The resulting green tinged off-white colour of the cleaned scales created an unfortunate contrast with the cleaned dark red of the the fluted walls. Paint analysis showed that the scales had been painted three times since construction.
The original scheme gave a translucent pinkish brown glaze caused by probably a resin varnish. There would have been a sheen but the paint was too thin to have a high gloss.
This discovery corresponds to Nash’s 1807 estimate document with includes ‘scales formed in stucco and polished or varnished’. This colour also ties the Nash Staircase more into the decorative scheme of the jib stairs and the first floor corridor. These spaces have an intricate decorative scheme on paper that was revealed and restored only a few years ago.
The original decoration was repeated possibly because the original developed a network of cracks, or there was water ingress (we know water ingress was a problem in the Picture Gallery from 1807). There is no dirt layer between the two schemes so this must have happened soon after the original decoration. They painted a very thin coat of lead white oil paint followed by a fresh coat of the pale pinkish brown varnish. The varnished scheme must have been in place for a number of years, as there is a thick layer of dirt separating this and the final light green seen today after cleaning. The presence of lead white indicates it must have been carried out before World War II. We carefully reinstated the pink scheme, after consultation with the National Trust panels and English Heritage to ensure we were making the right choice. The paint was created using conservation varnish mixed with yellow ochre and red oxide. Only teaspoonfuls of the pigment had to be used to create the right colour.
The paint was very thin and had to be applied with a large brush working quickly around the dome.
Three layers were applied to the fish scales and preparation work was done ready for the gilding to be reinstated around the lantern oculous.
You can watch a short video on the whole process by clicking here. All the images were taken by our conservators or our lovely Volunteer Roof Photographers Richard and Angela Knisely-Marpole