Repeat Bulkhead Leak

[Treefer32]

I have 2 3/4" bulkheads on my 340 gallon tank. 1 of them is 7 years old (since tank installation) and has never leaked, loosened or anything. Same bulkhead.
The second bulkhead is a different story. It started leaking 3-4 years ago and was a very very slow leak. I put a couple paper towels around it and it took 24 hours for the paper towel to be near saturated.

Well, I went to tight the nut and as I did, it released almost completely. I realized the nut was broken. I should keep 3/4" bulkheads on hand. Not sure why I don't, but thankfully the LFS had them and came out and installed the new one, wrench it tight about 1/2" turn. It's been fine for 3 years and noticed it beading droplets of water through the threads of the nut on the same side of the tank. Same bulkhead that had just been replaced a few years ago?

Why does this keep happening? I was able to hand tighten the nut (it was loose), I didn't see any cracks in the nut, so I think it's o.k. but why is it loosening and why is it leaking through the threads?

Open to suggestions here. I can't shut the tank down for 3 days to get a bulkhead. Open to ideas.

 

[D.WhiteShark]

Just my opinion but I have noticed the quality of things declining over the years. Depending on the manufacturer of the 1st Bulkhead, it's possible that the seals are just not made as well. Any chance the shop replacing the bulkhead looked to make sure there were no chips in the glass or leftover material from the other seal before installing the new one? Is the Seal on the correct side of the glass?

Edit: the seal should be on the same side of the flange regardless of orientation. (flange on inside or outside of the tank)

 

[Treefer32]

Seal is on the wet side for all my bulkheads. I'm going to drain the tank down to below the bulkhead and verify the seal and try siliconing the seal and retightening the nut. If that doesn't work I'll replace the bulkhead. Just need it to be reliable... :(

 

[Subsea]

Seal is on the wet side for all my bulkheads. I'm going to drain the tank down to below the bulkhead and verify the seal and try siliconing the seal and retightening the nut. If that doesn't work I'll replace the bulkhead. Just need it to be reliable... :(

I have extra bulkheads and I put seal on both sides. On thightening nut on dry side, I applies silicon grease to both sides of seal and to threads.

 

[RobertK]

Installing Bulkhead Tips

Bulkhead tips: 1. Always install bulkheads clean and dry, no silicone, teflon or thread lubricants. Silicone and lubricants cause the gasket to scoot out or not seal properly. Have you ever removed an old automobile windshield or other gasketed glass? The rubber vulcanizes to the glass with...

www.reef2reef.com

 

[D.WhiteShark]

Seal is on the wet side for all my bulkheads. I'm going to drain the tank down to below the bulkhead and verify the seal and try siliconing the seal and retightening the nut. If that doesn't work I'll replace the bulkhead. Just need it to be reliable... :(

Seal needs to be on the same side of the flange in order to seal correctly. It doesnt matter if the flange it on the dry side or wet side of the glass. The seal has to be on whichever side has the flange.

I personally wouldn't silicone in case you need to replace in the future, you'll be creating more cleanup for yourself

 

[jsmkmavity]

On a bulkhead already in service you could put a hose clamp on the nut and tighten it to prevent it from cracking and then tighten the nut some more. Be careful not to tighten too much because sometimes you can crack the flange of the bulkhead.

 

[Buckeye Hydro]

Use heavy duty bulkheads https://www.buckeyehydro.com/bulkheads-heavy-duty/

 

[UncommonSense]

If the glass hole diameter allows for it, my go-to these days is always Hayward bulkheads…

keep in mind that not all rubber bulkhead gaskets are created equal, but all rubber bulkhead gaskets have a finite lifespan/are a service item!