Thanks. The wings are sheeted with 1/32 balsa. My technique for skinning all of my foam-core wings is to use a light mist of 3M Super 77 on each part. Gus' plans for this model call for a built-up wing sheeted with 1/32. I prefer the strength and accuracy of a foam wing (it's easy to dial-in the necessary washout). This is fairly thin wing, but even with 1/32 sheeting, it's plenty strong once the leading and trailing edges are added.
I also like using foam (pink, blue, beaded, etc.) in place of formers and planking or hollowed blocks. It saves weight and precious balsa. I should note that I have white-beaded foam for wing cores, but I used the Omaha Steaks box as a test to see if it could be used for a 1/2a type model. The answer is yes and I got two wings (four panels) out of one large box.
For this model (actually, I'm building two, but this is the first one finished and flown), I completed the wing, joined the panels and then cut the ailerons loose and faced everything with 1/16 balsa. Again, this saves on balsa for trailing edge stock.
The original RCM build article is here.
I made some changes to the fuselage in that I House of Balsa-fied its construction. I've always liked how those guys worked out the construction of a P-51 and somewhat simplified it.
This model is very light and slippery, and, as you can see on the launch in my video, it's not lacking in the speed department with the Astro 020 brushless Merlin.