Thanks for the input guys. I will pick up some contact glue on my way home from work today. In my attic I have a wing from an old Q500 which has been worn out. (I know it sounds weird but the plane has many flights logged and the wing has turned soft after thousands of high-g turns...) That wing would be a great test object so what I will do is to weigh the wing section and then attach some litho to it. Afterwards I'll check the weight again to see how much it gained in the process. I'll get back when I am finished with it to share the results.

Regards, Jens