ORIGINAL: huck1199
You can put some bamboo skewers in your rudder to flatten it.
BINGO! on the skewers or small wooden dowels.
Yes, a .47 will power a Spadet with a 4mm wing. I fly a Deb with a 4mm wing (twin spars too) using a TT GP42 and it's fine. I use a slower prop; 11x5 to bring the thrust up.
If you don't have a router, use a big flat screwdriver to flatten the fold, after scoring with another tool. If you can completely crush the coro flute on the fold line, without cutting the coro (much) you will have a nice Leading edge. Fold the coro and put a load of books on top of the leading edge overnight. it will be easier to glue up the wing. Figure on clamping it closed when yoiu glue. Practice your clamping setup, before you apply the glue.
Jack