This kettle is big....hard to know how much is in there. I decided to add a sightglass. Plus....a Thermometer would be good....so...added a combo sightglass/Thermo....
Here is the kettle before I started..
Start with a small hole.
Then use the uni-bit...to make the hole the right size...
There we go.
Intalled the eye bolt on top to hold the tube.
Close up of the thermometer 
Next....I filled the pot a gallon at a time and marked the blue tape.
I applied the vinyl numbers at gallon increments....
Looks great and will help during the next brew.....Next up.... a pump to move liquids around....
