I had a bit of a struggle with some FT Builds - keeping the weight down!

Did a check: I found on the FT forum the following information

Weight of $ Tree Foamboard : 0.19 gram/square inch
Weight of Australian foamboard: 0.39 gram/square inch

Weighed mine (Foamboard, both sides paper laminated) 390 grams, 23.5"X 35"", thickness 6 mm

or 0.49 gram/square inch.

Ouch!!

Weight of 5 mm unlaminated board (biofoam) 132 grams, or

0.16 gram/square inch

For my next build I am going to try to use a judicious mix of both materials. The wing being heavier, it should be of biofoam, as should the tail feathers. Will need lots of tape reinforcement in strategic places

@sanjayrai55
Sanjay sir,
Should have asked me! Haha
My 6mm biofoam is 1 gm per 4 sqin. That's first thing I checked before starting on my slow flyer bipe.
Fixed cost - all onboard equipment wt
Variable cost - depron wt x wing area x 2 (to account for fuse and empennage)
Solved for wing area.
Voila! Need 2 sqft to go under 5oz/sqft
Don't want 4 ft span? No problem.
2 ft span, 6 inch chord, Two wings.
Hence Bipe.
Thanks for giving me an irresistible opportunity to pontificate!  

http://m.youtube.com/watch?feature=youtube_gdata_player&v=I7TyW3_lHNg&desktop_uri=%2Fwatch%3Fv%3DI7TyW3_lHNg%26feature%3Dyoutube_gdata_player

Thank you Iyer sir.

Please do us all a favour : pontificate a lot more