I did some research on the wing I messed up on and it looks like I made the wing more symmetrical by having the bottom leading edge angled like it is. You can see in the picture what Im talking about.
I am just a little nervous for my maiden on this Storch as I have spent way more time than I originally planed on it (What else do you do on a rainy day). It was supposed to be a replacement trainer to be crashed and not worried about...
I had the same fold in my wing. It seemed like the extra fold gave the wing extreme lift any time the nose was slightly up. Increases in pitch resulted in dramatic altitude increases, sometimes going vertical. It was very, very floaty. But, I am not a very experienced pilot so...
While not very easy to fly, it certainly wasn't prone to crashing, either. Landings were very soft. I also added a steerable tail wheel, so my initial angle of attack was less than a stock Storch, but still, takeoffs were trivial. If I taxied too fast, the plane would take off. I was on grass, and so was giving it a fair amount of power when taxi-ing. I think this made the tail lift very easily.
In the end, I remade the wing and was very careful to get a proper fold. I still ended up with a hint of the fold on the bottom by the spar, but just a hint.
I'm still not sure what causes this fold. I think maybe a hard spot develops in the foam board where the spar is glued on, making a fold easy to generate if you are not very careful to keep the bottom flat when doing BOTH of the top glues. i am using WR-DTFB.
On the rebuild, my first glue went well enough, and I thought I was home free, but on the second glue pass, I almost folded the bottom, but I caught it in time.
I forgot to the move the trailer edge spacers in 1/4" or so as specified in the plans. The trailing edge spacer is aligned with the back of the bottom of the wing. The wing is still flat on the bottom, so I'm not sure what effect this will have. Perhaps slightly less camber?
I'd fly it unless you have spare board to remake the wing.
One further note: I was using the standard 10x4.7 slow fly prop that comes with a C pack. I will try the 9x6 APC next time. A little bit more speed might help with the floaty feel. As I said above, I am not very experienced.
So, I destroyed the old wing just to see how strong it was. It was quite difficult to fold it - relatively speaking. Nothing snapped or gave way, just a gradual crushing of the mating components in the root. It's a nice design.
Mike