Thanks jben!
I wish I could build them with the 1x4 sides... I live in Canada though and it gets awfully cold in the winter lol.
The contact on the terminals is perfect! I tested every shelf and they all get the same heat as a test piece I soldered. I plugged them both into the wall and used my temp gun to test. I like it better this way because the heat tape is completely transferable! If you ever decide to build a new rack or w/e just take it off and put it in the new spot. It's also hella easy to do lol.