Looking to build a mash tun using a plastic cooler? This weldless bulkhead is just what you need.

Drill a 1" hole near the bottom of your cooler (many brewers remove the spigot that comes with the cooler and drill there), make sure that 1 washer and o-ring are on each side of the wall, and install the bulkhead. 

Then you can screw in a , , sight gauge, or anything else you'd like!