Tape comes in different thicknesses. I used urethane window sealant instead. The advantage is no water leaks in. You set the spacing of the window with some small pieces of tape to center it. Mask the window and the channel. Then squeeze in the urethane, wipe off the excess, remove the tape and let it set overnight. Flip it over the next day and repeat. Don't set the glass in a full bed or you will never get it out if you need to.
