How to Adjust a Large Sheet Metal Duct Elbow
Dealing with a duct over 16″ in diameter? Then chances are you’ve had to employ an adjustable 90° sheet metal elbow, but maybe had the elbow get stuck on you and not been able to adjust it to your desired bend radius. It can be a big waste of time without knowing a few handy tricks.
- Put on some gloves. They help with grip, and protect you from cutting your arm off.
- You often must straddle the elbow and hold one gore with your legs while turning others with your hands. It’s all about becoming one with the fitting, so wear comfortable pants.
- Examine the gores (a gore is each section of the adjustable elbow). The gores should slide within one another. When these get off track, the elbow cannot be adjusted.
- With a spiral duct, attach one end of the elbow onto the spiral duct and use the spiral to hold the elbow while adjusting.
- When the seam is completely lined up, your elbow is 180°. When the seam alternates to opposite sides every other gore, it’ll be at 90°.
- The Drop – Pick the elbow up to about stomach height and drop it on end. Make sure the entire end of the elbow hits the ground at the same time to avoid dings. This drop will sometimes loosen the part that is stuck.
- The Roll – Set the elbow on end and check for any flat sides. Then flip the elbow ends out and roll it gently on flat ground to “roll out” any flat spots. Put a little pressure into your roll, but pushing too hard will bust the elbow completely in half.
- The Straddle and Screech – Lay the elbow down flat on the ground with one end pointing behind you, and the other before you. Trap one gore between your legs and use your hands to turn as hard as you can. Remember to turn the elbow, not squash it down. The more oval the elbow, the harder it is to turn.
- The Surgeon – Put the elbow on an examining table and face an inch away from the gores. Follow each gore with your eyes, inside the elbow and out, and identify where the stuck point is. Once found, use a sheet metal hammer and flat screwdriver to realign.