Serge, I believe that the plywood is used so you will have something to sand the wing form, to. I believe that they are basically used for the purpose of construction and once they have filled that function, it really does not matter. You can use anything you wish. Just keep it light.
See N64KR at http://KR-Builder.org - Then click on the pics There is a time for building and a time for FLYING and the time for building has expired. Daniel R. Heath - Columbia, SC See you in Mt. Vernon - 2005 - KR Gathering -------Original Message------- I get the feeling that the plywood ribs are in fact there just in order to hold the foam during wing construction, and little else.
