Put the build aside for a few days to work on other projects and decide what to do. I ended up cutting off the damaged wing and made another from a sheet that closely matched the density/grain of the original. As it turned out, it was kind of a fortunate accident because it gave me some time to turn my attention to another area that’s bothered me for years: sanding in the dihedral angle on a glider’s root edge.
Below is the accepted standard for how it’s usually done with free flight gliders: prop the wingtip up at the correct dihedral height and sand the root edge.
The thing is, pressing down to hold it in place so it doesn’t move puts stress on the balsa and often causes some bowing and an inaccurate root edge, since it still manages to move around incrementally. Inefficient, not always 100% accurate, and often requires touching up the sanded area to ensure a clean, tight edge when glued to the other wing.
Yes I
could build a “ramp” type sanding jig to rest the wing on, but a much easier and faster hack is to make a jig with the
sandpaper set at the correct dihedral angle instead of the wing.
So I used a piece of scrap foam and cut out a 1/8” wide slot to hold a 1/8” piece of balsa bent to the correct angle.
The bottom half is the guide part that’s placed flush up against a straight edge (in this case just a piece of board). Sandpaper is glued to the top part, which is set at the correct dihedral angle to sand into the wing’s root edge. Simple! And all it took was a few minutes of cutting and gluing.
Very happy with the result: a clean, absolutely
accurate edge after only 4 passes.
So this mini build disaster ended up having a bit of a silver lining.
Now if only I could figure out a way to make a permanent dihedral jig with an
adjustable sanding angle, so I could have a machinist make one out of metal. Or have it 3D printed.