A few of us tried to find an easy reliable answer to minor foil wing repairs,
Tried epoxy putty and it was poor at sticking,
Then we found this JB epoxy filler,
It dries grey, so has to be touched up, but after a while that gets to be tiresome, so I leave mine or if very small then use a black marker pen,
The good thing about this one is it bonds so well, and sands easily with wet and dry paper.
Also I finish the area with my small powered palm buffer using a few dabs of resin polish or T Cut black, which works great,
Resulting in a durable repair.
Palm buffer was £12 new off EBay.