Secure the bottles: Make sure each bottle sits firmly, evenly spaced and level. Smooth the surface: Neaten the concrete around the bottles and centre opening with a trowel. Allow to cure: Leave to cure for 24 to 48 hours, keeping it slightly damp and protected. Demould carefully: Remove the suncatcher from the mould without loosening the bottles. Finish and seal: Sand rough edges, clean the glass and apply concrete sealer. Hang and enjoy: Add wire, chain or cord, then hang where sunlight can shine through the bottles.