Making the night sky
Step 1 Hammer nail into 1 corner of plywood. Tie 1200mm piece of string to nail and tie pencil to other end. With string taut, mark a curve.
Step 2 Use jigsaw to cut ply along marked curve. Use sandpaper to smooth rough edges.
Step 3 Paint 1 face of ply with undercoat (we tinted it grey so less topcoats were required). Let dry.
Step 4 Paint same face of ply in 2 coats of Blue Lobelia, allowing to dry between coats. Use a stipple brush to dab a little white pearlescent paint on top of blue to create a Milky Way effect. Let dry.
Step 5 Arrange fairy lights in an even spread on unpainted side of ply.
Step 6 Working 1 at a time, drill a hole just larger than diameter of each light and gently push bulbs through holes, flush with painted face of ply.
Step 7 Secure every light with a dab of hot glue at back.
Step 8 Flip ply over and, on painted face, screw in 10 evenly spaced screw eyes for planets to hang from.
Step 9 Wash walls to be painted using sugar soap and let dry.
Step 10 At ceiling, measure and mark 1200mm out from corner on both walls. Also mark point you want to paint to on your skirting. Use pencil along straightedge or a stringline to join marks.
Step 11 Apply painter’s tape along marked lines and press flat.
Step 12 Paint masked section in undercoat. Cut in with a paintbrush, then finish with a roller. Let dry.
Step 13 Repeat method in Step 12 to paint masked section in 2 coats of Blue Lobelia. Let dry between coats.
Step 14 Insert 1 toothpick in top of each foam ball. Holding toothpick, paint foam balls and foam ring with white gesso. Push toothpicks into foam block and let painted balls dry.
Step 15 To decorate each planet, hold toothpick and spin planet, applying craft paint using a small paintbrush as it spins. Insert back into foam block to let planets dry. Paint foam ring silver. Let dry.
Step 16 Seal all foam shapes with Mod Podge. Let dry, then remove toothpicks.
Step 17 To attach Saturn to its foam ring, push 1.25mm piece of gauge wire through 1 side of ring, straight through planet and out through ring on other side. Snip wire so there is 1cm extra at each end, then use pliers to flatten wire to outside of ring.
Step 18 So planets can be hung up, twist a small metal screw eye into top of each planet and secure with a dab of hot glue.
Installing solar system
Step 19 To hang ply assembly, drive in 1 ceiling hook towards back corner and 3 more hooks, evenly spread about 50mm back from front edge of ply. Where possible, locate a joist and drive a ceiling hook in at this point. Alternatively, install cup hooks with anchors.
Step 20 Mark position of ceiling hooks on unpainted side of ply. Drill 2 holes, 10mm apart, in each spot.
Step 21 Snip 200mm piece of wire and, from unpainted side of ply, thread wire through 1 ceiling-hook hole and back out other hole. Twist wire several times to form a closed loop and secure wire to ply. Make a loop at other end of wire (for ceiling hook to thread through) and twist several times to secure. Repeat for each set of ceiling-hook holes.
Step 22 With a helper, hook back loop of wire onto corner ceiling hook. Then hook front 3 loops of wire onto remaining hooks.
Step 23 To hang planets, tie 1 end of fishing line to a screw eye on ply, trim length to suit and tie to screw eye on planet at other end. Repeat for each planet.