Originally Posted by
speedracerntrixie
I find it best to do all your filling prior to applying fiberglass. This wing was stripped of covering, had quite a bit of filler applied to fix multiple low spots, then glassed and painted.
As much as I hate to admit it, I agree with Shawn here. Much lighter to fill your balsa with lightweight filler before you glass the surface. Any filler above the glass is only to fill the weave of the fabric.
Scott