How to remove a bulkhead when the threads are stuck tight

[trilinearmipmap]

This weekend I will be replacing a bulkhead that has a very slow leak.

Last time I replaced a bulkhead I could not loosen the threads to get the bulkhead off. The threads were welded tight together either by sand working its way between the threads or by salt creep evaporating and blocking up the threads.

I had to take a drill and drill through the outer plastic ring of the bulkhead to break the ring and then remove it, it took a long time and it put my tank at risk drilling right next to the bottom glass.

Does anybody have a better idea about how to loosen a stuck bulkhead?

[Black Phantom]

If its possible you might want to try vinager. Drip it on the threads and let it sit for a day,
The optimal thing would be to soak it but that might not be possible.
The other thing that really works with metal threads is wax.
The molecular structure when it melts is very fine and works its way into most cracks and such.
Do this after the vinegar and hopefully it unthreads.

If that fails "DYNAMITE"

[BCOrchidGuy]

You could always try a bulkhead wrench, not sure where you'd get it but they are a narrow flat steel wrench designed for tightening and loosening bulkheads. I'd never seen one before until I got an oceanic reef ready tank and it came with two, one for each size of bulkhead.

Doug

[Bryan]

Use a dremel with the cut off wheel disk to split the bulkhead nut.

[trilinearmipmap]

OK I did the vinegar and water thing and it came off no problem. Thanks.