OK here it is.....take a spray bottle and fill it with water and about 1/4 cup ammonia. Spray the wing untill it is very damp. Then secure the wing to a table using clamps or weights.
Then using a shim start to straighting the warp. Now if the warp is......say a 1/4 inch you have to shim the wing back to neutral and then 1/4 inch in the oppasite direction! This should not be done in one step. Shim it in small increments and come back every couple of hours and shim it a little more untill it is where you want it.
Now you must wait a few days untill the wing is COMPLETELY dry. Do not accelerate the drying with heat or monokote gun. Once dry remove the wing from the board and it should spring back slightly and be straight or close to it. Repeat as necessary untill the wing is fixed.
Like I said I built a Fazer with a NASTY warp and this method worked for me. It was perfect the first try.
Good luck
Brian