Words: Richard Crosland
Diagrams: Dave Gordon
Photos: Simon Bannatyne
A challenge can bring out the best in a woodworker and some years ago members of the NSW Woodworkers’ Association were invited to make a box from a single piece of dressed silver ash 1100 x 70 x 12mm thick.
I decided to make two boxes. They would be of octagonal, barrel-shaped or coopered construction, 109mm long and 57mm in ‘diameter’, with wooden hinges and locks.
Machining the components
Bring the silver ash down to a thickness of 7.5mm and cut off a 260mm length to provide the four octagonal ends, plus extra for saw cuts and trimming. This will leave about 840mm for the sixteen ‘staves’ for the ‘barrel’.
Rip this length into two square-edged widths of about 32mm (being silver ash these will inevitably bow as they come off the saw). A trimming cut and a second rip to about 26mm will give you the material needed to be rip-cut to an edge angle of 22.5° off vertical and finished (fig.1) at 23mm width. Each strip is then cross cut into eight lengths of 100mm.
To calculate the measurements of the octagonal ‘endplates’, wrap the eight staves together with masking tape into a barrel form and measure across the ends. These turned out to be 57mm, the wood set aside for the endplates was trimmed to four octagons of 58mm ‘diameter’. The extra millimetre was added for 0.5mm all-round sanding.
Achieving the octagon was done by first cutting the endplates 58mm square, then marking out along each edge in the ratio 7:10:7, or in this case: 16.8mm, 24mm, 16.8mm (fig.2).
Join the measured points as shown in fig.2 and cut along the lines to produce the octagonal shape. Decide which endplate belongs to which end and label them, making sure the grain runs the same way on both ends.
Set up the upside-down router (router mounted under a table) with a 3mm straight-cut bit to cut a groove 3mm deep and 15mm long on the inside face of five facets of the endplates. The edge of the groove (fig.3) closest to the centre of the endplate must be 8mm in from the edge (7.5 thickness of staves plus 0.5 left for sanding).
From the eight staves, select the five which will form the fixed part of the box and the three to form the lid. Trim the three lid staves to 94mm length. Cut offset tenons on both ends of the five staves so the tenon is flush on the inside face of the stave (fig.4).
This can be done on the tablesaw or with careful marking out, by hand with a dovetail saw. Have a dry run with the five tenoned staves and the two endplates to make sure that all the components are meeting up as they should. Do not glue up yet!
The hinges are made from ‘ply’ which is built up from nine thicknesses of 0.6mm silver ash veneer laminated together. The grain of each leaf is positioned at 90° to the one next to it, as in commercially prepared plywood. Use a small foam roller to apply urea formaldehyde glue with liquid hardener to each sheet. Make up a 200mm square sheet, and while you are at it, make up another of five veneer thicknesses for the handles and sliding bolts.
Cut the nine laminate ply (5.4mm thick) into 30mm wide strips. Slice off a 2mm strip from each edge and run a 1.5mm square groove in the two edges of the wide piece, using a 1.5mm slot cutter in the upside-down router. So what you now have should look in cross-section like fig.5.
Glue the 2mm strips back onto the edges from which they were removed, binding them on with masking tape until the glue dries. Take care that glue does not block the slot.
The hinge knuckles need to be marked out and cut at 10mm intervals along both edges of the laminated strip. Again, careful marking out and cutting is essential here regardless of whether you do it on the tablesaw or by hand with a dovetail saw and chisel (fig. 6).
On the upside down router, round over the edges with a 2mm radius rounding-over bit and then take a 2.8mm deep trench down the centre of one face so a cross-section of the piece looks like the sketch in fig.7.
This strip of prepared hinge material can now be ripped to two 8mm widths, its final width, then the two halves checked to see that they interlock with one another as in fig.8.
A length of 1.2mm diameter galvanised wire acts as the hinge pin. Run a 2.6 x 2.6mm rebate on the two hinge staves (one on the body of the box, the other on the lid) to accommodate the hinge fig. 9.
Cut the two halves of the hinge to the correct length (94mm) for the box and lid staves and then glue them in place. Use a minimum of glue and hold them with masking tape. Take care they interlock with one another so their ends are flush.
Bolts and handle
The bolts and handle are made from the five veneer (3mm) thickness ply which you should already have made. Take the stave set aside for the lid and rout a trench down the centre of its inside face 10mm wide x 1.2mm deep. Next, down the centre of that, rout a 3mm x 3mm trench so the opening stave is like the one shown in fig. 10.
Now rout 2 x 3mm slots right through the opening stave as shown here on the outside face as in fig.11. Also rout a 20mm x 2mm deep x 3mm wide groove for the handle centres on the length and width of the stave on its outside face.
The bolts themselves are cut with a dovetail saw from the 3mm ply in a shallow ‘T’ shape (fig.12). The handles are also cut from the 3mm ply (fig.13). The vertical edges of the upppermost bolt ‘handle’ are rounded over by sanding. One end of each bolt is sanded to a round cross-section to go into the hole in the endplate.
The 10mm wide cover plate which holds the bolts in place is cut from two thicknesses of veneer laminated together (1.2mm) and trimmed to the correct length. It’s a good idea to polish the bolts before fixing them inside the opening stave by gluing the cover plate on, which should now be done. The handle can now also be glued in place.
Now a full dress rehearsal is needed, so wrap the five box staves together with masking tape and clamp the two endplates on gently. Strap the three lid staves with masking tape and hold in place. Touch the ends of the bolts with lipstick and push them to make contact with the endplates. Take everthing apart again and centre the lipstick marks on the endplates with a brad awl and gently centre-punch them.
Select a drill bit that matches the diameter of the bolt ends and drill a 4mm deep hole very carefully.
You will now you will need to do one more dry assembly to check bolt holes, then give the inside surfaces a final sand with 240 grit paper. Glue the assembly up and use masking tape and light clamps to secure it while the glue dries.
Remember, if the hinge goes wrong, you still have plenty of the original sheet of nine laminated thicknesses of veneer left!
Sand off any excess edges on the endplates and perhaps a fraction off the ends of the lid if it is rubbing on the inside of the endplates.
The little round ring boxes are made from the leftovers of the silver ash glued together, using laminated veneer for the top and bottom discs. The hollow is drilled with a 25mm Forstner bit and the lid plug using a 25mm plug cutter. All components are rounded off on the disc sander and glued together, hopefully concentrically. The green felt is an optional extra.
Richard Crosland teaches woodworking classes in Alexandria, NSW. Learn more at crosland.com.au