Cristophe

After reading your post, I removed the flap servo's to inspect the spar. Mine has a Solid Carbon fiber spar that is Sandwiched with ply between the wing skins. It forms an I beam of sorts. It passes through 2 wing ribs that are also ply. It looks to be pretty solid but for some peace of mind I went ahead and covered as much as i could get to with 30 minute epoxy. Here are some pics the angle is hard to shoot but you might see what I am talking about.

Joe