This is an excellent example of a mid 19thC Gothic-style slipper chair that retains its original finish. The chair is made of walnut with a rosewood faux graining. Over the years the shellac coating has deteriorated enough to cause the film to "crackle". The added layers of old polish and waxes has collected dirt and obscured the surface. It was popular to use oil, mostly linseed oil, to "feed" the wood and finish, which can NOT be done. The oil has attracted the grime and darkened on it's own as it polymerized ("cross-linked") locking in the dirt.
The objective of this treatment was to remove the deteriorated polishes and oils to expose the original shellac coating and preserve the faux grained rosewood. Once the dirt was removed, the "crackled" shellac needed to be saturated to allow the light to pass and reflect off of the highly decorative faux graining.
That was accomplished by creating an artificial saliva solution in the lab as the water-based cleaner. Once rinsed and dry, Paraloid B-72 (15% in xylene) was brushed on to fill the crazing of the shellac and create and homogenized clear film. Xylene was the chosen solvent due to the fact that the B-72 is highly soluble in it, but has no affect on the shellac. This makes the treatment completely re-treatable by being able to remove the B-72 and expose the original surface unaffected.
