as i am sitting here looking at how thin the heat tape actually is i don't think using a router to make a groove will work. Its like 1/16 of an inch thick. Also, my tubs have a bulge around the outside of the bottom of the tank, about 1/2 wide all around. Do you guys think that this 1/2 touching the heat tape directly on each side would be alright? if it would that would leave a very nice 1/4 inch air gap across the width of the tub to vent. What do you all think? think this will work? also, is there any kind of tape or something i could put on heat tape for the tub to slide on? I feel like the 1/2 of the tub on each side will eventually wear down the tape. thanks!