Good Afternoon all;

  Covering open bay wing with plastic film covering...  Obviously the covering is adhered around the perimeter, but is it also necessary (or recommended) to adhere it to the individual ribs (half-ribs as applicable)?

  My 'gut' tells me that adhering it to the ribs will increase the torsional rigidity and stiffness of the wing...

  If the answer is yes, should it be adhered prior to shrinking the covering, or after?

Thanks in advance,
Dave

  It's best to NOT stick iron coverings to anything but the perimeter of what you are covering, until you have shrunk in sufficiently to remove any wrinkles. You get best shrinkage that way. If you seal it to each rib and spar first, you get less shrinkage, and only in the area surounded by where it is sealed. I have learned to always pull iron on coverings as tight as possible while initially attaching, get the wrinkles out that way first, and save some shrinking ability for down the road when the sun and heat makes it relax a bit. Once it is shrunk, then seal to the ribs, spars, etc. if you feel you have to, and on some designs, it is necessary for strength and twist resistance and strength.
  Type at you later,
    Dan McEntee