Early plywood: conservation of a 1760s mahogany tray

By Caleb Sims

This pierced fretwork mahogany tray arrived in the furniture department with an accompanying bag of bits. This fretwork is made up of three layers of mahogany veneer which are glued together to form a thin but stable strip - just like modern plywood. The design is then cut out using a fine saw.

All the loose pieces required sorting and re-adhering in position

Replacement mahogany plywood was made using three qualities of timber, mid quality went on the inside, lesser quality went in the middle and the best quality went on the outside. This was done to mimic the 18th century original.

Here the new plywood was used on the straight parts of the fretwork gallery.

A silicone rubber mould was made of the curved parts of the fretwork

This technique was used to cast a small amount of missing parts where losses were either too small to justify wood or fractures too awkward to work in small carved wooden pieces - all in the name of saving original material.

These replacement pieces were cut and adhered into position

The loose joints were re-adhered using warm animal glue and a square block was used to hold the joint square as it dried.

All the replacement pieces were coloured using water stains and the surfaces were finished using wax. A silicone free aerosol wax was used for the gallery to prevent damage with pressure from a cloth. A paste wax was used on the main board.