I appreciate all the valuable thoughts gentlemen.

I will try to do what I always do if I can not answer a question. I will go back to the basics, which in this case is physics. I have a friend in Germany who may be able to help me. I hope. My times in school when I knew a little about that are to far back. :cry:

At this point it appears that the only way to really solve the problem is testing. Which is one of the most difficult things to do. You would have to apply the same conditions to the same materials to get comparable answers. I doubt taht anybody is equipped for that.

I summarize all I learned like this:
There are different ways to build shear webs. As long as the fit is tight they all seem to work. That being said it may be left to your own preference which way you go and how much effort you want to put in it.

I enjoy building and if I find a way to build more stable without adding weight I WILL go that way, no matter what the effort is. I see a point in what some of you said about getting the same result with less effort.

I did not only look in reeinforcing the spar with carbon as you suggested Keith, I actually did that before I even installed the shear webs. If that spar ever breaks there will be nothing else left to repair anyway.

Cheers

Steff