The sticky heat pads I have used in the past have had a paper of some type covering the sticky side. I might be a little concerned about leaving the paper on there, just wondering if that could be a fire hazzard. My personal opinion would be to just stick it on without foil tape, and if you can't pull it off and re-use it later, then just buy a new one. Or you could just purchase a non sticky heatpad and tape it.