Shower arm stuck

[Knscarlato]

Hi All,

I have a shower arm that is completely stuck in the threads of the water supply pipe. I have doused it with CLR, white vinegar and wd-40, using both locking pliers and a monkey wrench with absolutely no give. Any suggestions on what else I could try?

 

[Jeff Handy]

Apply PB Blaster or a similar penetrating oil to the threads.
Tap firmly a few dozen times on the shower arm with a screwdriver or similar tool, the vibrations help the oil get into the threads.

Do this a few times, a few hours apart.

Try again to unscrew the shower arm after at least twelve hours of letting the oil penetrate.

WD 40 is NOT penetrating oil.

You also could try heating up the threads with a hair dryer.

Don’t start a fire behind the wall.