Tunbridge Ware Box archive
Friday 14 October 2011
Dennis Keeling takes influence from ancient Tunbridge Ware and creates this lidded box using offcuts of Corian
Incorporating pictures into turned vessels is very popular with segmenters in the USA. But it was also made popular nearly 200 years ago by the turners of Tunbridge Wells in England and Sorrento in Italy.
Tunbridge Ware, as it is known today, was crafted by gluing thousands of strips of different coloured woods together to form a mosaic picture.
This is not like marquetry using a veneer; this is a bit like Blackpool rock with the picture going all the way through the glued up composite.
I thought I would revive this old tradition but instead of using strips of wood, I would use Corian which I had available in many different colours. A castle was a widely used design by the turners of Tunbridge as the ramparts worked very well with the mosaic pattern.
Tools used: Tungsten-tipped shear scraper, negative-rake side scraper, negative-rake flat end scraper, skew chisel and hand plane
After trial and error I finally found that 3mm (1/8in) square strips of Corian give you enough mosaic components for the 40mm (1 5/8in) segment width. Start by cutting the 13mm (1/2in) Corian sheet into slabs which measure 300mm (11 3/4in) long. These can then be cut on the bandsaw into 4mm (5/32n) x 13mm (1/2in) strips. You can now cut the strips into 4mm (5/32in) square lengths. Use white, granite, black and green strips for the design. The door needs to be made from a strip of mahogany (Khaya ivorensis); the top then needs to be hand planed to give the apex - you can't plane Corian
Clean up the 4mm (5/32in) square lengths on the disc sander, bringing them down to approximately 3mm (1/8in) square. They don't have to be very accurate. You will need over 100 square sections for this design
I framed my early attempts in a 'U' shaped trough using 6.5mm (1/4in) white Corian, but this limited the size of the mosaic picture
Construct a wooden trough from scrap timber and line with polythene sheet; this will enable the mosaic picture to be built up to the full width of the segment - 40mm (1 5/8in). Use white Corian strips 6.5 x 40mm (1/4 x 1 5/8in) for the top and bottom of the segment stack
I found that gluing each strip separately into a composite proved an impossible task. It is easier to construct sets of glued-up strips:
Four across for the stone work and a thin strip of black glued each side of the middle of a wider strip of the same material to form the windows. Glue grey and white strips together to form the battlements. Use a white two-part epoxy glue to simulate mortar in the stone work and use a clear CA glue for the black windows
Fix the wooden door centrally to the base piece of white Corian using CA glue, then glue the layers of brickwork using white two-part epoxy glue. Try to glue up the whole composite in one process - it gets difficult at the half way mark. Squeeze the segments along their length to ensure the glue is uniform along the length
When the composite has been glued up, add the top strip of 6.5 x 40mm (1/4x 1 5/8in) white Corian and clamp the whole composite to get the air bubbles out and to square off the section. It took me four attempts to get this right; the first three versions came out too crooked
After the glue has cured - usually after 24 hours â€“ cut the ends off and clean up the section for cutting. Sand the sides flat on the disc sander ready for cutting the segments on the bandsaw
Cut the individual segments on the bandsaw - they need to measure 15mm (9/16in) wide to give plenty of clearance. There
is enough length to get 16 segments from the one composite, which is enough for two boxes
Sand the edges of the segments to the 22.5 degree mitre angle on the disc sander. Be careful not to sand too much; they should all be roughly the same size. Try to alternate the segment sides for sanding the mitre angle - it makes the box asymmetrical
Before the segments can be glued together it's better to prepare the base. Mount a round piece of 6.5mm x 110mm (1/4x 4 1/2in) diameter white Corian on a wooden faceplate using a paper glue joint. Draw a 100mm (4in) diameter pencil ring on the top to show the centre for gluing up the segments of the box body
Dry mount the segments on the base, using a rubber band, to ensure that they come together as a ring. Any badly fitted joints need to be re-sanded on the disc sander until they all fit together cleanly
It's easier to glue the segments to the base and together all at the same time. Use white two-part epoxy glue between the segments and the base. Gently hold them in position using a rubber band. Do not clamp them otherwise the glue will be squeezed out of the joints
When the glue has cured - usually after about 12 hours - the base can be mounted on the lathe and the outside turned. Use a tungsten-tipped shear scraper to gently clean up the edges and get the box running true. Have the lathe speed quite slow here - about 500rpm - this will avoid the Corian splintering
Finish the outside with a flat negative-rake scraper. It's only the burr that is cutting so you need to re-hone the scraper several times to get a good finish
Clean up the inside and bring down to size; initially using the tungsten-tipped shear scraper, then afterwards use a negative-rake side scraper. Use a skew chisel to clean up the bottom in flat scraping mode
The top is made from a round disc of 13mm (1/2in) white Corian that measures 105mm (4 1/8in) diameter. You first need to glue it to a wooden faceplate using a paper joint; this will enable it to be easily separated later. Recess the top to about 5mm (1/4in) in size to fit the box using a flat end negative-rake scraper. Finally, bring the outside down to the same size as the box body
Break the box away from its wooden faceplate and fit it to the top already mounted in the lathe. Hold it in place using a small steb centre on the tailstock. Clean up the base with a flat end negative-rake scraper and slightly undercut it to allow it to sit firmly
Bring the outside of the base down to the same size as the box body using a tungsten-tipped shear scraper
You can now finish the outside of the box, including the lid, using the negative-rake flat end scraper
Sand the box using Abranet sanding discs - starting at 120 grit and working up to 1,000 grit. Finally, polish using a car cutting paste to give a semi-gloss sheen