I personally never use the adhesive as I don't use glass tanks for any of my snakes..actually to be honest, I use heating pads for humans (with three settings, no auto shut off) and I just slide these under one third of the container I keep my snakes in. The low setting heats the tank perfectly without getting too hot.
For the UTH you have, duct tape will be fine to hold it to a new tank but if you have a solid shelf/stand, just lay the UTH in the space between between the frame...there should be enough space the heater isn't crushed or the cord. If not, prop up one end of the tank with folded cardboard or anything sturdy enough so you have a quarter inch of space or a bit more.
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PHLdyPayne