I have the same issue. I may try to glue in some additional nose ribs, like those made of lexan that Sam did, going through the lightening holds to try to push the dimples out. Maybe somebody has a better idea.....
Not lexan.......luan mahagoney ply (doorskins).
Tom,Could you estimate the total amount of added weight of the two false ribs made of blue foam for the entire wing?Thanks,JimWe had the same problem on our LEU wings after our Ohio Valley humidity went to work. I made some false nose ribs with 2" thick blue foam, then cut the false ribs into three pieces, the center piece a wedge shape, each small enough to fit through the lightening holes in the spar. Then applied some quick set epoxy and assembled the pieces where they needed to go, and forced the wedge shaped piece to push the other two pieces to eliminate the dimples. Held in place until epoxy set. It worked OK, but would not be useable in the sections with no lightening holes.Later, when we built the DE, we put in one false nose rib (thin luaun plywood) between the plans located nose ribs. This helped a bunch, but we still got some slight dimpling in a couple spots. If I ever built another wing, I think I would go with two false ribs in each bay, maybe made of 1/2" blue foam. Strong enough, but as light as possible.
Do like Leonard and Bob said, but unless you live in Houston or San Antonio, add moisture to the plywood with wet paper towels before you epoxy it on. T-88 is not affected by it... Google it. West Epoxy was designed for boats. Google it. The point being, if you attach the plywood when it is as damp as it will ever be, it can only tighten when the wood dries out thus no dimples, and no added weight...