Tankard starts as a Ø235mm x 2mm thick pewter disk and is worked into the final shape with various spinning tools.
The completed tankard height is 165mm with a capacity sufficient to contain 568cc (1 British pint).
Left. The spinning chuck onto which the metal is laid down to produce the final form. This one is constructed in two pieces, from aluminium, and is split at the waist to allow later removal of the lower section. When spinning is completed the lower section is removed after cutting the base with a trimming tool, the resulting disk is reused as the internal base to the tankard.
Centre. The resulting tankard body.
Right. A completed tankard, much loved, with acquired patina.
Left. Master handle pattern. The handle pattern started out as a piece of 19mm (¾") thick aluminium plate. A paper outline of the handle was glued to it and the rough shape sawn out. Initially a die grinder and carbide burr were used to remove the bulk of the excess material, next progressively finer files were used, followed by abrasive cloth and finally polishing. The pattern has two rods fitted which provide support for the pattern when the mould is being made and form the sprue and riser in the mould.
Right. Handle mould. The is cast in Dow Corning Silastic 3120 RTV silicon rubber. The mould was formed by placing a sheet metal frame work around the handle pattern and pouring the rubber mix in till it came up the to pattern centreline. When the lower half was cured the pattern was removed and the slight flash caused by the miniscus was trimmed. The mating face of the mould was coated with a thin film of vaseline and the pattern replaced. The mould was then completed by pouring the top half. Dowels are provided to ensure correct alignment of the two halves which is particularly important when the mould warms in use and becomes more flexible.
Left. Handle in as cast condition.
Right. Handle after cleaning up. The handle surface is initially cleaned up using a fine file. Due to the softness and ductility of the pewter, the filed surface can then be burnished to remove the file marks and then polished ready for fitting and attachment to the tankard body.