Step 2 – Create the Intakes
This is by far and away the hardest part. Use a step drill bit to make three, 1” holes evenly spaced around the drum 2” above the base. Multiply the diameter of your drum times 3.14 and then divide that result by 3 to get the distance of the space needed between the holes around the barrel. For example if your drum has a 23.5” outer diameter, then space the holes 24.6” apart.
Use a small drill bit and make a pilot hole. Once the pilot hole is drilled, switch to the step drill bit and continue drilling the hole. As you approach 1” on the step bit, stop and test fit the nipples often. You want a perfect fit and want to avoid making a bigger hole than needed.
Thread a ¾” x Close black pipe nipple into each hole. To do this, tighten a conduit nut on one end of the nipple. The close nipples we used bulged in the center so the conduit nuts wouldn’t thread to the center. Thread the nipple from the inside of the barrel until the conduit nut is tight against the inside. When working inside the barrel, consider using a headband lamp or have another light source available so you can see what you are doing.
Then, slip two, ¾” washers around the outside of the nipple. You may need to use the step bit and mill the inside diameter of the washers out enough so it slips over the nipple and is flush with the outside of the barrel. For the ball valve nipple, you may need three, ¾” washers. For the capped nipples, tighten a conduit nut on the nipple after the washers.
On two of the external nipples, screw on a cap. On the third, screw the ball valve on so the end of the handle turns towards the outside of the barrel and the top of the handle faces the top of the cooker.
