Personally I'm quite happy to stay at 60 kg (as we are now), halveways so to say.



My design is still using alu beams and alu mast. It can use carbon tubing but a new standard alu alloy is taking over the market that is just strong enough for usage in beams and masts.

Its 6060-T6 / AlMgSi 0.5 F22 with a garanteed minimum elasticity boundery (0.2%) value of 160 MPa.

It is cheap, very corrosion resistant, sufficiently hard and quickly becoming THE standard alloy that even local common household hardware stores are stocking (even when they don't know it). The 0.2% boundery is just enough to use it for a unstayed mast, but the final test this winter will tell.

Currently, I'm testing axles made from this variety and they are holding up extremely well. That is they have hold up under a 120 kg pilot getting himself airborn and landing on a hardsurface; among other things..

I have just purchased 18 mtr tubing of 6060-T6 for 140 Euro's. That, I call cheap. I've also bought two unstayed alu masts of 5.5 mtr length ready to take a sleeved sail for a total cost of 250 Euro's = 125 Euro's per mast. The sleeved sail for it (currently 5.5 sq. mtr. area for the initial test) was 400 Euro's. Basically, (collapsable) mast, sail+battens, and boom+ fork was a total of 750 Euro's INCLUDING shipping.

Indeed, I have no money to play with at this time, but somebody is giving me a small sponsorship for landyachting. I'm using this to also do some testing on the setup I'm planning for the F12.

Anyway, I'm quite happy to start off the minimum ready to sail 60 kg (possibly with corrector weights) and when a 4 mm ply + all alu boat can be build at 50 kg then we can always lower this value.

I have never campaigned for a 70 kg minimum weight, that is just assumed by others who don't read the posts very closely. I have campaigned for not getting to far away from what can be had by rotomoulding and for not setting the limit at what is technically possible but economically unviable.

Wouter