David,

Check my thread and you'll see how I used the microglas. I put it only in the area of the empennage interface. You don't even need to make it smooth that way, just scuff it up so it'll stick.

I've been trying to decide if I want to notch the vertical to the top block as well. I haven't built a plane in a long time that just called for a simple butt joint here. I guess on the original design a glass layer may have added strength. It is a fairly wide interface.

Mitch