Install a Sight Glass fitting

Installing a Sight glass fitting

Before you start, disassemble and clean the fittings with warm water and a mild cleaner like baking soda, Powdered Brewer Wash, or unscented oxyclean.

Tools needed:

1/8” Starter bit
Step bit or hole saw. The best hole size is just a bit larger than 13/16”. 7/8” will work but will be loose.
Metal cutting lubricant
center punch
emery cloth or fine grit sand paper
Heavy drill that has a large 1/2" chuck that fit step bit. Use a helper if you have one.

If drilling for 3/8” fittings you will need a 5/8” drill bit.

Position locknut just above the curve of pot, mark the center with a permanent marker and use your center punch so bit won't wander. Have helper hold the kettle or keg and drill starter hole with 1/8” metal bit. Use slow rpm's (100) and lots of pressure. Use lots of lubricant or hole will case harden and ruin the bits. Clean all chips and burrs from inside and outside the hole. Use sandpaper or deburring tool (dremel) to smooth any scratches or sharp edges on the hole.

ALUMINUM DRILLING:  This metal cuts much easier than SS.  Moderate speed and low pressure is best. It tends to grab the bit and can warp the metal quickly if you lose control of the vessel when drilling.  USE A HELPER.

Wrap 5 or 6 wraps of white teflon tape on each side nipple threads. Yellow gas teflon tape is thicker 3 to 4 wraps is enough. Wrap in direction of the thread. Add an oring, and thread locknut on one end. Place through wall of keg from inside.  2nd oring is a spare.  Add washer(s), the elbow or Tee and hand tighten. 

Grip the locknut with locking pliers and use locking or adjustable pliers on the elbow to further tighten down the fitting set. Do not overtighten. You just want it snug against the metal. If you have to tighten it all the way down just make sure the o-ring does not pop out.

Wrap several wraps of teflon tape on the large NPT thread on the compression adapter fitting and thread into the 90 or Tee. Remove nut from the compression fitting and slide it on the tube.

Add the two small o-rings and insert tube end in the compression side of the adapter fitting and hand tighten the nut. The orings will form the seal. Do not put teflon tape on the small thread on the compression side. Close any valves on the pot and fill enough water to submerge the coupler/locknut inside and watch outside for leaks.

Locate the eyehook at the top, drill hole and use nuts to support the polycarbonate tubing. If in a kettle and you will fill above the nut you will need some teflon tape / small o-rings to seal the hole or it will weep. For a slow drip, slightly tighten the fitting until drip stops. If drip gets worse check the o-ring for proper install and  ensure it is not popping out the sides of washer or locknut.