Originally Posted by Sundancer
Sorry to disagree Al, but this being a tailless model the washout is not there to prevent tip stalling, it is there so that the model will have enough stability to fly! In other words, the washed-out wing tips are acting like a very short moment, high negative angle tailplane. As you say, it is important to get both wings equal and then fine pitch trim adjustments can be made by the adjustable elevons.
It might not need a whole 10 degrees if it was made with an airfoil which had near zero or positive pitching moment.
Suggest something in between the airfoil used here:
and a normal, thin, flat bottom airfoil.
You might check out the airfoils in Barnaby Wainfan's Swallow. These are for a slightly swept flying wing with taper.