The high aspect rudder blade used in Le Havre and Northampton works well from a light breeze to a gale! However, in very light conditions I've decided a slightly lower aspect blade will help turn the boat more effectively at very low or virtually zero speed. I've been using 2mm pivots on Footy rudders to provide a slim and light profile. Interestingly I have some 2mm carbon rod and 2mm carbon tube and the tube is stiffer! The tube has proved reliable but it does need a short section of 1mm rod glueing in the end of the pivot where the rudder horn grub screw grips. I use regular epoxy resin with some fine cut glass strand mixed in and this formula holds the balsa-card-balsa laminate together well and retains a very straight blade. A relatively 'light weight' band saw cuts the 2mm pivot slot very quickly and accurately. The pivot is glued in place with epoxy and held in place with masking tape until cured to avoid a hard ridge which would be time consuming to smooth down flush with the profiled balsa. The glass cloth is very light weigh stuff which I think is in the region of 40 gsm. The layer of coloured card works really well to help speedy but accurate profiling of the balsa. It comes in at 5.2 grams finished with paint.