Oddly enough, all you need are some floating shelf brackets. There are several different kinds. The ones linked below require a dado cut in the shelf to make them invisible. Others have a flatter wider flange which can be nearly invisible assuming your board is wider than the flange but will leave a slight gap between the wall and the shelf. If your wall is nice and flat, I prefer the ones I have linked below.https://www.amazon.com/BIGTEDDY-Adjustable-Floating-Invisible-Concealed/dp/B01KZWRJ38
I am not able to see your picture, but I made some alcove floating shelves with 1/4" plywood and 1x2s. Mount the 1x2s to the wall, nail the plywood on top, and face the front with a 1x2 to add bulk and hide the braces. Stain it and you're finished
Quote from: lthenderson on August 29, 2018, 08:39:08 AMOddly enough, all you need are some floating shelf brackets. There are several different kinds. The ones linked below require a dado cut in the shelf to make them invisible. Others have a flatter wider flange which can be nearly invisible assuming your board is wider than the flange but will leave a slight gap between the wall and the shelf. If your wall is nice and flat, I prefer the ones I have linked below.https://www.amazon.com/BIGTEDDY-Adjustable-Floating-Invisible-Concealed/dp/B01KZWRJ38These look like the best sturdy option, but how do I slide both the left and right side into the corner?