The wind vane has a fixed portion, usually in the shape of a cross, which marks out north and the three other corresponding corners of the compass. Above that is an arrow, which needs to be free to move around to show the wind direction in relationship to the compass direction.
The arrow needs to be able to catch the wind from one end, so some sort of sail or wing is usually used for this, while the other end is slightly weighted to give some stability.
To ensure the bamboo is sound in the weather, I'm painting it - and this requires me to lightly sand the surface before I apply the paint. I've made the wing and the compass directions from thin sheet tin cut to shape and slotted into the ends of the bamboo, but marine ply will work as well as anything.
Either way, there's plenty of opportunity for you to add some extra embellishments.
Step 1: Select two diameters of bamboo. Use a 40mm to 60mm thickness (it needs to be thick enough to insert the chain swivel into the end) about a metre long and three to four pieces 10mm to 20mm in diameter and about half a metre long.
Step 2: Sand the shiny surface off each piece of bamboo and paint with white acrylic paint. At the end of each 10mm thick piece, cut a 40mm slot, into which the wing and the compass directions will slot.
Step 3: Cut a 100mm section of the thicker piece of bamboo. Insert one end of the chain swivel into the end of the bamboo and hold in place using Selley's Knead It epoxy putty. Once the putty has cured, after around 20 minutes, insert the other end of the chain swivel into the longer piece of bamboo and again hold in place using Knead It. Shape the putty so the water runs off.
Step 4: Through the centre of the shorter length of bamboo, drill a hole to fit the 10mm thick bamboo, 50mm above the chain swivel. Insert one of the 10mm-thick bamboo lengths and hold in place, again using Knead It.
Step 5: Through the centre of the longer length of bamboo, drill a hole to fit the 10mm-thick bamboo, 50mm below the chain swivel. Insert one of the 10mm-thick bamboo lengths and hold in place using Knead It. Repeat the step 20mm below this, but this time set the bamboo length perpendicular to the first, so it forms a cross.
Step 6: Using tin snips, cut out the wing, arrow and compass direction shapes to slot into the end of each piece of bamboo. Drill a couple of 2mm holes through the bamboo and tin, then sew together, using wire. Cover with Knead It and paint.
Step 7: To erect the wind vane, use a compass as a reference to make sure the compass points are pointing in the right direction. You could also set the wind vane on a longer bamboo pole attached to a fence.