Thanks Rolf, sharing is the only way to progress. Yes, It's the F 12 mast. I made the double barrel tube myself, but in the heat of the action I forgot to take pictures, but I will make another one for the Pixie of a “nice lady”, so if not to much distract by her I will try to correct my mistake... This spar is in weight about half way between alu and carbon, 5,3 kg. Bending characteristics as Scarecrow stated.