How to assemble a living-hinge box: tabs, seams, lids and finishing

A Hingesmith box comes off the laser as five or six flat parts and goes together in about ten minutes, without clamps. The order matters, and the scored marks on the base are there to be used.

What you have

• Base plate, with slots for the wall tabs and a scored guide line showing exactly where the wall stands, broken at each slot.
• Wall strip, or strips: one piece of plywood with the hinge cut into it, tabs along the bottom and top edges, and a short seam tick at each end. Walls longer than your sheet are split into strips that butt-joint at low-curvature points.
• Rim: a ring the shape of the box with an opening in the middle. It sits on the top tabs of the wall and locks the outline.
• Lid top, carrying the lid art, and a lid insert that glues under it and drops into the rim opening. A snap-lock lid's insert has flexure nubs that click past the rim; a magnetic lip has a lid magnet layer and 6 mm seats in the rim.

Before you start

• Keep the parts in the orientation they were cut. Mirroring a wall strip puts the tabs on the wrong side.
• Peel any masking, then flex the wall strip gently along its whole length a few times. The links loosen up and the wrap goes on evenly.
• Dry-fit first. Glue comes last.

Wrapping the wall

1. Find the seam: the end of the strip with the short scored tick. Push its first bottom tab into the matching slot in the base, with the strip standing on the scored guide line.
2. Work round the base. Bend the strip just ahead of each slot, press the tab home, move on. On tight curves, a thumb inside the box and fingers outside, close to the bend, gives you control.
3. With more than one strip, the second starts where the first ends; the seam ticks on the base show where. The strips butt edge to edge and the rim holds them.
4. The last tab meets the first. If it will not reach, the strip has wandered off the guide line earlier; back up a few tabs and re-seat.

The tabs are drawn half a kerf oversize and the slots half a kerf undersize, so they press in with thumb pressure and stay. If they fall out or will not go in, your kerf differs from the file's: see measuring kerf.

The rim and the lid

1. Press the rim onto the top tabs. Start at the seam and work round, as with the base. The box is now rigid.
2. Glue the lid insert centred under the lid top: a thin bead of PVA, line it up with the opening in the rim, press and leave it under a book for twenty minutes. Check it drops into the rim before the glue sets.
3. Snap-lock: the insert's nubs click past the rim. If it is stiff, the first few uses ease it; do not sand the nubs.
4. Magnetic lip: glue 6 mm disc magnets into the seats in the rim and in the lid's magnet layer, poles matched. CA glue, a small drop, and check the pull before it cures.

Glue and finish

• Once everything fits dry, a drop of PVA in each slot before the tab goes in, and a rubber band or two round the box while it dries. Wipe squeeze-out.
• Keep glue off the hinge links. Glue stiffens them and shows under finish.
• Finish after assembly: a light sand of the edges, then oil or wax. A thick varnish before wrapping would crack at the links; see finishes that keep the hinge alive.
• Smoke stains on the hinge wipe off with a damp cloth and a little dish soap; let it dry fully before oiling.

If something fights you