We have had the good fortune to find gilding of around 300 years in near perfect condition, but it is more likely to be found degraded in some way, re-gilded or painted over.
Gold leaf itself does not tarnish or deteriorate, however, it is extremely thin and will wear if constantly rubbed or handled. Damage to gilding and gesso is a common problem generally caused by knocking and mishandling.
Environmental conditions are also known to have serious effects:
• dry conditions cause wood to shrink away from gesso resulting in voids which causes splitting and flaking of the gesso
• damp conditions cause the glue in gesso to degenerate, eventually turning gesso back into powdery chalk.
These problems can usually be resolved:
• flaking gesso can be consolidated
• voids and powdered gesso filled with new glue and the gesso re-instated.
In the 19th century, gilders were not interested in preserving original finishes. In their desire to obtain a new gilt finish they often washed off any remaining gold and then applied new gesso over the existing gesso and bole surface. This gave a smooth finish on which to gild, but unfortunately obliterated the finely carved detail of the original gesso surface. It is possible to carefully remove layers of later gesso, paint and gilding, revealing the original surface with it's finely carved detail.
Once the original finishes have been revealed, cleaned and conserved, restoration to the damaged areas can be carried out. Missing elements can be re-carved in new wood, gesso can be re-instated and the fine detail modelled to match in. Finally, new gilding can be applied to all repairs and worn areas, then toned to blend in with the 18th century finishes.
Our carvers serve a 5 year apprenticeship in wood and gesso carving and also conservation.
Any missing carved elements can be replaced, in wood, as they were originally made. Gesso is applied to the wood which is carefully modelled and re-carved, thus sharpening the outline and decorating the surface with shallow veins prior to gilding. Many other workshops carry out repairs using fillers and resins and do not re-carve any detail after gesso is applied.
Some examples of woodcarving, gilding and restoration work are illustrated below.