A person picks up a piece of balsa and say wow, how light. A person pics up the same sized piece of coroplast and says wow...it's heavier than balsa...therefore, anything built out of it will be heavier than the same thing built from balsa. Wrong. In a Spad, there are no ribs, webs, covering, supports, ply doublers...etc. The ugliest of Spads...the Big Ugly, has a wing loading of less than 14 oz/sq. ft. It's so ugly the ground repells it...but it works because it flies better and lighter than any of my Falcons or Kadet did. The CoroSpit and Corostang were modeled as 1/12 scale airplane deminsions and come out LIGHTER than their balsa or foam counterparts. The Debby rivals the wing loading of the Avistars depending on engine and landing gear used, and the Spadet rivals the wingloading of the LT-40. I will admit that over the last 4 years, the square gutterpipe has become hard to locate...I just found out last week that it doesn't meet newer housing codes in many areas...and is being phased out in favor of the 2 x 3 inch stuff that every LOWES in the universe carries....so...it looks like I'm going to have to build one out of that stuff. Many have done it already and it works fine...oh yeah...and it's lighter than the square stuff.