Hello Wade:
Sounds like a good technique. I also glue canvas to masonite with success. I use polymer medium as the glue and use unprimed canvas.
The one thing I do, and which I will recommend to you is to wrap the canvas around the board with at least 6 inches glued to the backside in corner flaps. This way, if at some later point, your canvas needs to be removed from the board, you have extra canvas on all sides and they don't have to crop the picture to remount it.
Hope that helps!
