bulkhead removal/reinstall

[nostradamus]

125 Gallon saltwater drilled on backside - about 4 inches from top on either side. One of them leaks, so am trying to remove it - but it goes round and round in circles when I try to unscrew it. Is there a way to cut it/remove it without breaking the glass?

illustration of aquarium and location of holes below
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[hobogato]

try spraying the threaded area with the nut with vinegar and let it sit for 10 minutes. the vinegar will dissolve any sand or salt crystals that are stuck in the thread and binding it. if that doesnt work, use a drimmel tool with a spiral cut bit and cut the nut on each side so it falls off in two pieces.

[nostradamus]

cutting is probably what I'll have to end up doing. is there anything I should look out for when I drimmel it out - so that I do not shatter the glass?

[hobogato]

dont touch the glass with the drimmel bit. you should be able to cut thru the nut without getting too close to the glass, just go slow and be really careful.

[Bill S]

What Ace said. Then buy a replacement - they aren't that expensive. Just don't hit the glass.

You want to split the nut. Don't worry about the washer part of the nut - once you get it split, it should come off.

Alternatively, you can use a GOOD cut-off wheel, and cut the nut between the hex and the flange, straight thru. Like above, stay away from the glass. I'd put a bunch of blue painter's tape around the area, a couple of layers thick, in case you "bounce" it will hit that and not the glass.