There are many different ways to put a spar into the corsair for ultimate strengh,I used barbon rod and cut into the top of the wing and burried it into the wing,this runs from one end to the other of the wing,it takes time to put it in and hold it down but works great after you have epoxied it in to place.second was to shove 8'' bambo scewers into the wing where it starts to dip for the gull from the fuse I used about 6 per side and now it is good and stiff Im not to scared to pull up on the stick abruptly as the power 10 pulls me around.I also intalled a 1/16 carbon rod across the bottom of the elevator to give it more consitancy to the side that the control horn isnt on,oh I drilled the control horn as close to the surface of the elevator as I  could so the strengh would be through  the horn and not the foam.If you want I could post a picture of this.There is a post on r/c groups of how to use a road sign and cut a full aluminun spar shaped as the gull wing.
Greg.