Robin, What you are essentially saying is that you want a wing with nothing but spars and skin. No foam no ribs. Just a fiberglass skin will be quite flimsy as pointed out by Mark. It will probably take a lot of plys to build up the skin to a thickness that might support its shape, but at that point the weight gain will counter the initial effort. You see that done on carboard R/c planes. But those things generally very little power loading and are low aspect ratio wings.
Even if you are able to figure out a way to make the skin light you still need something that takes the shear loads. That is what the foam and the ribs do for you. It IS structural. The skin glass fibers on the bias help transfer the shear forces to the foam or ribs, but will not support the complete load in the absence of the the foam or ribs. The wing will collapse because of drag and twist. I think Mark Langford's KR is made with ribs (2 ribs?) and a sandwich skin. The sandwich skin is certainly a good idea as it is lighter and strong then a coreless glass layup. I don't know if that method has any weight advantage over the method described in the plans. My recommendation is not to proceed with your intended modification. Regards, Ameet Savant Omaha, NE --- Robin Wills <krvia...@bigpond.com.au> wrote: > My understanding is the foam is completely > non-structural, and by > removing it, I could possibly save up to 20Lbs. > Proposed method is to glue the foam in place, per > plans, but apply duct > tape over the foam between the spars and around the > leading edge, glass > the wing, then pop the foam loose, leaving the > nicely shaped fibreglass > behind. > > Comments anyone? > > Cheers, > Rob. > > Robin Wills > Second Person, Pacific National > KR-2 19-4594, Ser# N111 > > krvia...@bigpond.com __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
