Conservatory Bench Woodworking Plan
This product would look perfectly at home in a conservatory or garden room. Its slatted construction allows plenty of light to pass through and around it while keeping the weight down so that it is easily moved. For all that, it is remarkably strong, and being of generous length, it could even be used as a day bed if provided with a few loose cushions. It is made of iroko, a naturally hard and durable wood, so it would be equally suitable for use outdoors as a garden bench during the summer.
• 3.6m (12ft) of 50 x 50mm (2 x 2 in) hardwood for the legs
• 10.7m (35ft) of 75 x 22mm (3 x 7/8 in) hardwood for the rails
• 2.45m (8ft) of 65 x 19mm (2.5 x 3/4 in) hardwood for the large slats
• 14.7m (48ft) of 19 x 19mm (3/4 x 3/4 in) hardwood for the small slats
• 4m (13ft) of 38 x 25mm (1.5 x 1 in) hardwood for the seat battens
• 1.4m x 900mm (55 x 35 in) of 12mm (1/2 in) birch plywood for the seat
• Eight 100mm (4in) bolts and cross-dowels
• Wood glue
• 8mm (5/16 in) wooden dowels
• 25mm (1 in) and 38mm (1.5 in) wood screws
The bench incorporates bolts and cross dowels to connect the ends to the center sections. providing a firm and positive connection while allowing the unit to be taken apart if it needs to be transported. Cross-dowels are tubular connectors that are barely detectable when inserted. They are threaded to receive long bolts that attach the two end frames.
1. Make the end frames first. Cut the legs to length, and scribe 12mm (1/2 in) wide mortises with a mortise gauge as shown. Do this with the front and back legs clamped together, flush at the bottom. The diagram (figure 1) gives the dimensions required to set out the end frames.
2. Cut the mortises 32mm (1.25 in) deep to leave enough room for the connecting bolts. Pare the ends and sides of each mortise true and square, making sure that the bottom is free of obstructions.
3. Set out the tenons on the cross rails, then clamp the rails together in pairs to mark out the mortises for the vertical slats. The wider, central slat is positioned first, then the smaller slats are placed at equal intervals along the rail.
4. Cut the tenons on the rails, and pare down with a shoulder plane for a good square fit in the mortises. Note that the shoulders only run along the wide faces of each rail. The mortise is the full height of the rail in this case.
5. Cut all the mortises in the rails. You can drill to a depth of 32mm (1.25in) and chisel them out, as shown, but there are a lot of them, so if you have a drill stand or, even better, a mortise attachment for a power drill, it’s well worth setting up to do this.
6. Cut the tenons on all the slats and pare them to fit, clamping them together so that you can true up (square) all the shoulders in one operation. This ensures that all will be drawn uptight when the frame is glued together.
7. Before assembling the frame. sand all the surfaces that will be difficult to clean up later – it saves a lot of time and trouble.
8. Glue all the slats and fit them to the rails to make a sub-assembly that can be connected to the legs in one operation. It should not be necessary to wait for the glue to dry in this instance; the assembly should be rigid enough to proceed to the next step.
9. Clamp each frame together with a pair of sash cramps (clamps), keeping them flat on the bench to prevent any twisting, Wipe off any excess glue and continue with the slatted back section of the bench while the glue dries. Lay one frame on top of the other to make sure they are identical in size.
10. Clamp the bottom rail in a vice and insert all the vertical slats. If you have worked accurately and methodically, all the narrow slats and all the wider slats should be interchangeable. Double check each one before applying glue, however, in case it should need easing slightly.
11. Attach the top rail, starting at one end of the assembly and gradually working your way along. You will find it very useful to have an assistant support the free end. Tap the rail into place with a rubber mallet, locating all the slats before applying the cramps. Make sure the ends are aligned and the assembly is square, and leave to dry.
12. Mark the positions of the connecting bolts and dowels on the inner faces of the end frames. Note that the back is inclined outward at the top to provide a more comfortable seating position. The 50mm (2in) legs allow an angle of about 3 degrees within their width, which makes all the difference. Use a bevel gauge to set out the positions of the back rails.
13. Each end of each rail is fitted with two 8mm (5/16 in) diameter wooden dowels to locate it accurately and prevent it from twisting when the bolt is tightened. The central hole is drilled to suit the diameter of the bolt. Use center-points to mark the hole positions on each rail – note the block of scrap wood clamped to the bench to hold the rail square.
14. Clamp the rails horizontally to drill the holes in the ends. The holes for the connecting bolts should be drilled to a full 75mm (3 in)depth to allow plenty of clearance. Get someone to help you by standing to one side to check that your drill bit is truly horizontal.
15. Drill a hole for the cross-dowel, intersecting the bolt hole, and insert the cross-dowel from beneath the rail. Note the slot at the end of the dowel, which is used to align the hole to receive the bolt. When the slot is parallel to the sides of the rail. the bolt should enter the dowel easily.
16. Countersink the holes for the bolts in the outer faces of the legs so that the heads sit just below the surface. Align the wooden dowels, tap the end frames into place and tighten the bolts with the key provided. The result is a discreet and immensely strong connection.
17. Cut two battens to the full length of the front and back rails, and screw them in place to support the seat. The seat can be made of any suitable sheet material – in this case, 12mm (1/2 in)plywood strips were used to provide a degree of flexibility.
18. The two endmost strips should be notched to fit around the legs. Note that the top edges of the plywood have been radiused with a rounding-over cutter to prevent splinters from catching on the upholstered seat cushions. Sand all the strips smooth before fixing.
19. Screw the plywood strips to the battens, using a block of wood to ensure regular spacing. Make sure that the screw heads are countersunk well to prevent them from snagging on the cushion material.