Originally posted by snsmith
Given the choice, I prefer 3/32"...gives me more room for sanding to get a nice finish on the covering and the weight difference is almost negligible unless you are scraping for every ounce. Let's say you are building a 72" plane, around 1000 sq in of wing area. An extra 1/32" of skin thickness, using 10lb density balsa adds less than 3 ounces total to your plane...
10LBS DENSITY..... Wow!!! you building a brick? You can build a wing of 1000 sq in with 1/16" 6lb density balsa and still get a strong wing. Use 1" wide c.f 5mil or even fiberglass strips as spars, 2 on top and 2 on the bottom at least 20 inches out. Put a square of c.f. over the aeileron cutouts top and bottom. Use Probond urethane glue as it penetrates well when activated with moisture. First seal your skins with 50/50 thinned nitrate dope and this will control the absorbtion of glue into the skins. Use an 8lb grade balsa for tips and L.E. and T.E. (this wing uses a wing tube and a ply rib at the end of the tube)
I just finished up a set of wings for a pattern plane with retract setups and the precovered weight is 12 oz per panel. On my current plane the wings came out to 15 oz covered with no retracts (fixed gear) and servo a heavy ine to boot(FMA 5601M).
The built up wing on my Hangar 9 CAP came out at just over 3lbs (its just an ARF) and I am thinking of building a foam wing using this technic to try and make it lighter.
It can be done with carefull planning and the right stuff.