STEP 1: Punch a 1-1/4" hole in the bottom cover
We use a weatherproof 2-gang metal outlet box and two metal blank covers to cover up the connection end of the heating element. These heavy metal boxes and covers are meant for installing outlets or light switches in wet locations so there's no risk of water or any other liquid getting inside if you hose down the kettle or have a spill.
We use a 2-gang box (made for two switches or sets of outlets) to make installation simpler. You may find you have enough room in a single gang box, but odds are it'll be a bit tight.
Any industrial box and cover that is considered safe for wet locations should work as long as it's metal. We want a metal box to make it easy to ground the whole setup properly.
Two metal blank covers are needed as well: One for the outside and another that will be permanently epoxied to the bottom.
The weatherproof outlet box is too thick and uneven to create a nice flat surface to seal up against the kettle, so we use one of the blank covers on the bottom of the outlet box. Drill a pilot hole using a regular drill first and then use the GreenLee 1-1/4" chassis/radio punch to create a nice round hole that is 1-1/4" in diameter. This hole will let the threads of the heating element pass through.
We don't recommend using hole saws or step bits to make this hole in the cover as you want it to be precise with nice clean edges. A punch like this slowly slices through the metal creating a perfect hole by drawing a circular cutting edge towards a flat edge.
Make sure to purchase a chassis (sometimes called radio) punch to make this hole. Conduit punches are also available but their punch size does not actually match the size of the hole they make (the punch size is actually the NPT (national pipe thread) pipe size) - just to make things confusing! When in doubt double check what size hole the punch will make before using it. The punch you want is the GreenLee 1-1/4" chassis/radio punch which makes a hole that is 1-1/4" (1.25") in diameter.
We'll be using the same punch again to make holes in the Blichmann kettles later in these instructions.
Center marked and measured with a Sharpie permanent marker:
Drill a pilot hole in the center with a regular drill and bit, and then install the GreenLee 1-1/4" chassis/radio punch as shown below. Turn the nut on the bottom of the punch to draw the upper cutting half towards the bottom, creating a perfectly round hole without any rough edges:
The finished hole:
Two photos showing how closely the heating element fits in the new hole (the black rubber washer that was included with the element will not be used):