I am toying with the idea of building a light cove around the entire living
room (about 28'x22') then use recessed lights and other lights towards the
middle.

My idea is to attach a 2x6 horizontally to the concrete block wall, which
will make a "shelf" about 6" wide. I will route the top side on the outside
to put a small notch in which I will insert a thin strip of frosted glass or
fiber glass about 3 to 4" tall so this will form the "lip" of the shelf.

Inside the shelf I will put 48" long florescent light fixture and chain them
up all around.

This seems simple to do I just need some suggestion on how I would secure
the 2x6 sideways to the concrete block wall. I don't want to use any
visible braces. Any thoughts?

Thanks in advance,

MC