Building My Own Rack -- Heating Tips Needed

When building my rack do I need make little insets on each shelf for the heat tape or just set it in each shelf? How do I "tape" it down into each shelf? This is my first rack and I am super excited about it, but I want to make sure it is right :) any advice would be appreciated!

You should be able to tape the flexwatt directly to the shelf. I use foil tape to hold it down...

It really depends. If the tolerance isn't too tight, simply placing it on the shelf is what most people do. Without a Router, it is difficult to make recesses for the Flex. The simple act of sliding the tubs over the flex without a lot of downward pressure isn't too big a deal.

Use Aluminum tape to hold it down. About $6 for a large roll at Home Depot or Lowes. It conducts the heat well and keeps it tackiness as well.

Don't forget to make sure you have somewhere for the thermostat probe when all the tubs are in place. And have fun with the build!

I would advise against using aluminum tape to hold your flex watt tape down. I understand that a lot of people do use it with success but I wonder if your flex watt ever got a short in it because of ware and tare from the friction of the tub. Your aluminum tape would conduct electricity and could become a hazard.
If no router is available, do you have access to a table saw? 1" stack dado blade set on a table saw will recess your 1/8th real fast. I pin down my flex watt with thumb tacks, very easy to remove the flex if need to.
Hope you get your rack figured out, have fun with your build:)

just throwing it out there if you use thumb tacks dont puncture the heat grid make sure it is only on the clear plastic arround the edge