I grouped them together in stacks of 9 and glued them together with the Loctitie Power Grab Adhesive in the pressurized can. It was awesome and super easy to use. Because it did such a great grab of holding I didn’t have to use clamps. Bonus! On each additional stack of nine I used the previous stack to line up the shims so they were exact to each other. No worries if a little of the glue seeps out, go ahead and wipe off the excess – it does dry clear.