These bulkheads are driving me insane!!!

[Randy Holmes-Farley Verified Community Expert]

I managed with some help to get my tank (heavy Oceanic 120) onto the stand. Now I have to install bulkheads through the stand bottom. Not easy, but I managed.

Leak testing in the overflow: uh oh. 2 leaked right away, and one only showed drips 24 h later.

I do not recall having so much trouble last time...

The holes look to be designed for 3/4" bulkheads, and they go in fine, but there is too much play (gap between the bulkhead OD and the hole ID) and if they move around any, water begins to leak around it because the gasket (seemingly normal sized based on reading many online bulkhead descriptions) does not have enough overlap. Pulled them all back out and ordered larger OD rubber gasket that I hope work.

But maybe last time I used 1" bulkheads. I don't remember having 3/4" pipes in the overflow. Thought they were bigger... Tried my 1" and they just barely do not fit. In fact, they go in a little, jam, and are hard to get back out.

Next option was sanding down the threads a bit on a 1" bulkhead. Not too much because obviously they need to grip strongly. That seems. to work. It goes in, and at least as I pull on it, the threads hold.

Dilemma...

Go with 3/4" bulkheads, less possible flow, and still not sure if the wider gasket solves the problems
or
Sand down 4 of the 1" bulk heads, get higher flow, but maybe risk a thread failure.

I don't really care for plumbing... lol

 

[Troylee]

I’d sand down the 1” bulkheads and roll with those! If the nuts still fit good and thread on easily I don’t see it being a issue honestly.. the threads don’t need to have those super sharp edges.. other option is a rat tail glass file or a dremel with a sanding drum disk in the glass and open the open the holes up a bit.

 

[rtparty]

What is exact measurement of each hole? Schedule 80 bulk heads might fit better

 

[SomeHappyFish]

3/4 bulkhead would require a 35mm hole, is the hole bigger? With the 35mm hole there is a bit of a wiggle room which is fine.

Sanding down would work because the seal is made with the gasket and the pressure applied on it, made by the threads.

 

[Besieged]

Far from a plumber, but paranoid about leaks.

I was actually just reading the BRS article about overflows when discussing drilling a refugium on another site, and it indicated most are 1" - 2".

3/4" does seem pretty limiting. Maybe if you sand the 1" bulkheads, you could seal the threads with silicone? CA glue, I would guess, would be more permanent than desired... same with Weld-On 4. Maybe epoxy? I don't know just how it would handle in-between the threads in terms of trying to break it loose after the fact, but in cleaning up some dried up rock recently that frag epoxy had been used on, I noted it isn't super resilient.

Still, I would think maybe a thin ring of silicone around the threading, and another ring at the edges of the interfaces (once it's tightened up) would solve the problem.

 

[Nor'easter Reefer]

My vote: Sand the threads on a 1". If you worried about thread failure, order second nuts and double nut it.

 

[Randy Holmes-Farley Verified Community Expert]

What is exact measurement of each hole? Schedule 80 bulk heads might fit better

It's hard for me to get to them now to measure, but its probably in the 41 mm range since a 42 mm (claimed) OD bulkhead only needs some sanding to fit.

 

[SomeHappyFish]

I'm not a plumber but a pipe fitter, has long has the gasket is flat and pressure is made on the green parts here, the threads don't matter about preventing a leak.

The only issue is the sanded threads might cause the nuts to be loose which will prevent adequat pressure causing it to leak IMO.





I had to cut my bulkhead here because it overlapped with the silicone from the overflow box, never leaked and never will since the gasket is flat and pressure is applied correctly.

Sanding the glass would work better but it's more risky and takes longer.

 

[Randy Holmes-Farley Verified Community Expert]

3/4 bulkhead would require a 35mm hole, is the hole bigger? With the 35mm hole there is a bit of a wiggle room which is fine.

Sanding down would work because the seal is made with the gasket and the pressure applied on it, made by the threads.

Yes, substantially bigger. Maybe 6 mm bigger.

 

[Randy Holmes-Farley Verified Community Expert]

I'm not a plumber but a pipe fitter, has long has the gasket is flat and pressure is made on the green parts here, the threads don't matter about preventing a leak.

The only issue is the sanded threads might cause the nuts to be loose which will prevent adequat pressure causing it to leak IMO.





I had to cut my bulkhead here because it overlapped with the silicone from the overflow box, never leaked and never will since the gasket is flat and pressure is applied correctly.

Sanding the glass would work better but it's more risky and takes longer.

Yes, my concern was when tightening, I might strip the thinned threads. Might have to be careful about tightening. lol

 

[Dom]

It's hard for me to get to them now to measure, but its probably in the 41 mm range since a 42 mm (claimed) OD bulkhead only needs some sanding to fit.

I wouldn't be comfortable making a modification such as that, particularly with plumbing and the potential for leaks. But I'm not a gambling man.

 

[SomeHappyFish]

Try a 1" bulkhead from different brands they might vary 1-2mm.

 

[rtparty]

It's hard for me to get to them now to measure, but its probably in the 41 mm range since a 42 mm (claimed) OD bulkhead only needs some sanding to fit.

A Sch80 3/4” needs a 1 5/8” hole or roughly 41.275mm

 

[Randy Holmes-Farley Verified Community Expert]

Thanks folks.

On a related note, both bulkhead sizes have gaskets with some raised concentric rings on one side. Is that side supposed to face the glass or the the bulkhead?

 

[Troylee]

Thanks folks.

On a related note, both bulkhead sizes have gaskets with some raised concentric rings on one side. Is that side supposed to face the glass or the the bulkhead?

I put them towards my glass myself. They normally come installed that way.

 

[Besieged]

Thanks folks.

On a related note, both bulkhead sizes have gaskets with some raised concentric rings on one side. Is that side supposed to face the glass or the the bulkhead?

Do the rings match up with where the bulkhead would mate to it? If there isn't a matching rim on the bulkhead itself (i.e. it's flat), I'd put the ring on the glass-side, that way it can be compressed by the bulkhead fitting and form a suction seal.

 

[troublemaker]

If they fit but incredibly tight, my vote is sanding the glass with a drum on a rotary tool, if that’s even an option. It sound like it’s close. It’s easy for me to recommend this, it I would probably get lazy and shave down the bulk head threads also. But it would always be in the back of my head what I did, and would probably bite me in the butt down the road.

 

[SomeHappyFish]

Thanks folks.

On a related note, both bulkhead sizes have gaskets with some raised concentric rings on one side. Is that side supposed to face the glass or the the bulkhead?

The rings help create a better seal by compressing against the smooth glass surface, reducing the risk of leaks

 

[rhitee93]

This may not be helpful, but here is some data based on the tank I had built a while back. The builder put in 2" holes for my 1" schedule 8 bulkheads, and a 2.5" hole for the 1.5" schedule 8- bulkhead.

Also, in my opinion, reducing the diameter by sanding down the threads is not likely to reduce the holding strength of the threads enough to cause leaks. They really shouldn't need to be that tight. I would be a little worried, however, that you can change the geometry of the thread engagement enough that they might start to bind rather than slide smoothly.

I don't really care for plumbing... lol

I bet you had a class on blowing your own glassware at one point ...

 

[Dan_P]

I managed with some help to get my tank (heavy Oceanic 120) onto the stand. Now I have to install bulkheads through the stand bottom. Not easy, but I managed.

Leak testing in the overflow: uh oh. 2 leaked right away, and one only showed drips 24 h later.

I do not recall having so much trouble last time...

The holes look to be designed for 3/4" bulkheads, and they go in fine, but there is too much play (gap between the bulkhead OD and the hole ID) and if they move around any, water begins to leak around it because the gasket (seemingly normal sized based on reading many online bulkhead descriptions) does not have enough overlap. Pulled them all back out and ordered larger OD rubber gasket that I hope work.

But maybe last time I used 1" bulkheads. I don't remember having 3/4" pipes in the overflow. Thought they were bigger... Tried my 1" and they just barely do not fit. In fact, they go in a little, jam, and are hard to get back out.

Next option was sanding down the threads a bit on a 1" bulkhead. Not too much because obviously they need to grip strongly. That seems. to work. It goes in, and at least as I pull on it, the threads hold.

Dilemma...

Go with 3/4" bulkheads, less possible flow, and still not sure if the wider gasket solves the problems
or
Sand down 4 of the 1" bulk heads, get higher flow, but maybe risk a thread failure.

I don't really care for plumbing... lol

Dremel the hole a bit bigger so you can preserve a bit more thread.