Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
Cut a piece of lead that's 7.5cm larger than your piece of marine plywood all the way round, with metal snips. Position the wood in the centre of the lead and fold over the edges so it is held tightly to the board. If necessary, trim off any excess at the corners for a neater finish.
Cut three triangles of lead, 30cm x 25cm x 25cm. Fold over a 5mm strip along the longest edge to give a softer edge. Cut about 3cm off the bottom point of the triangle.
Mould the triangles into a shape resembling half a funnel - it helps to form it around a small flowerpot. Pinch the bottom edges together and leave a 1.5cm flap at each side, which will be used to attach the pocket to the lead-covered board.
Lay the lead-wrapped board flat and arrange the three pockets. Hammer them to the board with the clout nails, three on each side of the pocket (cover the hammer head with an old rag to prevent scratching the lead). Line the pockets with plastic, piercing it at the bottom for drainage, and plant up.