C18th Liverpool Delftware Plaque

A dated Liverpool delftware plaque; biscuit coloured fabric with tin-glaze and cobalt blue decoration. Decorated with the armorial of Merchant Taylors and motto, and inscribed, “THIS SEAT WAS ERECTED BY JOHN HARRISON AND HENRY HARRISON OF LEVERPOOLE 1722”.  This plaque commemorates the purchase of a pew in 1722 by John and Henry Harrison, who were related to the school’s original founder, John Harrison. It was sited in St. Michael’s Church in Crosby, Liverpool, on the wall over the pew near the middle of the church. It is thought to have hung in the church until it was demolished in the C19th, after which it was acquired by the school. It was made at the pottery of Alderman Thomas Shaw, which was at the end of Fontenoy Street and Dale Street in Liverpool.

On receipt of the plaque, previous repair was present; it had been broken into three sections, repaired with an epoxy resin, missing areas in-filled with epoxy resin and titanium dioxide, and retouched.

All over-painting was initially removed using a scalpel blade under magnification. The surface (both back and front) was then cleaned by firstly applying a weak solution of non-ionic detergent and deionised water, applied by stencil brush, followed by the controlled use of a Derotor Steam Cleaner GV.

As much in-fill material as possible was removed with a scalpel blade. The join lines were then painted with deionised water to form a barrier layer, followed by the application of environmentally friendly paint stripper, after which the plaque was covered in Clingfilm to concentrate the action of the paint stripper. This process was repeated several times, but there was no movement in the joins; it was ineffective. The plaque was finally fumed with a solvent in a sealed container for several days; this too was ineffective.

It was decided not to continue trying to dismantle the previous joins as this could actually put the object at risk of further damage; the adhesive used in the previous repair was stronger than the ceramic body itself.

All chips, along join lines, edges of glaze and clay body were consolidated with a 20% solution of an acrylic resin in acetone, applied by brush. The glaze layer was then mimicked using a coloured epoxy paste; a mix of an epoxy resin, fumed silica and artist’s dry powder pigments. The epoxy fills were refined with various grades of sanding fabric.  They were further hand-retouched with a clear acrylic glaze and artist’s dry powder pigments. Retouched areas were refined and polished with sanding fabric. The chipped areas to the unglazed back face of the plaque were filled with a mixture of plaster based filler and artist’s dry powder pigments. These fills were refined with a scalpel and various sands papers and then retouched with acrylic paints. A very thin protective layer of epoxy resin with a small addition of a fumed silica, was applied along the filled and retouched areas of the upper face. Once cured, this was refined with various grades of sanding fabric followed by a plastic polish.