# Sealing Bulkheads



## BenHugs (Jan 13, 2007)

I'm setting up a 255g tank that has been drilled and was wondering the best way to seal the bulkheads.
Should I..... 1.Leave them dry and let the rubber gasket do the work
2.Seal them with silicone.....or
3. Use silicone grease

Thanks all :wink:


----------



## cevvin (May 2, 2008)

Im wondering the same thing


----------



## Guest (Jul 26, 2008)

You shouldn't have to use anything else to seal it. If it's tight enough it should be leak proof.


----------



## herb (Mar 23, 2003)

usually they seal with nothing added, i have had one that i had to silicon to seal, but that is one in about 30 fitings i installed, i would say try it with nothing, only use other stuff if that fails for you.

herb


----------



## Tigerdat (Jun 29, 2008)

You should just rely on the gasket for sealing. Don't install them with silicone its almost a guarantee that it will leak at some point(especially if its a plexi tank) I don't like using the silicone grease mostly because its real easy to over tighten the standard aquarium bulkhead and crack the flange. Sometimes it can take several days to months for the flange to fail. I no longer use the aquarium quality bulkheads, the gray bulkhead is a schedule 80 plumbing part. You can see the difference in the thickness of the flange and the gasket.

notice how thin the flange is if it fails you tank leeks









The plastic in this bulkhead is much stronger than the plastic aquarium product bulkhead.


----------



## BenHugs (Jan 13, 2007)

Thanks for all the info everybody :thumb:

The bulkheads I have look like something you would use in a pool or something??? They are light grey with white nuts and much thicker than the black one pictured above.

I'm new to the drilled tank club. I sure hope they don't leak :?


----------



## DanDee (Mar 7, 2008)

I just put mine in tonight and used a little Vaseline...no water yet so I don't know if it will work or not! :lol: 
Dan


----------



## fiupntballr (Jul 7, 2004)

should make a mini article and put it up on the library for this!


----------



## BenHugs (Jan 13, 2007)

DanDee said:


> I just put mine in tonight and used a little Vaseline...no water yet so I don't know if it will work or not! :lol:
> Dan


I'm not sure about vaseline it might react with the rubber gasket?????


----------



## Joels fish (Nov 17, 2007)

Petrolium products of any sort should never be used with natural rubber seals and a fair number of synthetic rubbers aren't compatable with petrolium either. The vasoline will eventually cause the rubber to swell and weaken and the gasket to fail , leaving you with a nice wet floor and dead fish. *DanDee* if you can you need to remove the gaskets and replace them, and make sure you remove any traces of the vasoline from the tank and the fittings. It's not going to fail tomorrow, but it will fail.


----------



## DanDee (Mar 7, 2008)

Joels fish--Thanks for the tip! Someone else on this forum had recommended the Vasoline. I will remove them tonight. 
Dan


----------



## Joels fish (Nov 17, 2007)

No problem. The effects of the vasoline take a while to become evident, but eventually the rubber softens so much that it just comes apart. The swelling forces the gasket out away from the bulkhead and the distortion of the seal allows the water to get past. If you need a lube on the gaskets just wet them with water, but there should be no need as lubing can allow the fittings to be over tightened and put stress on the bulkheads and glass and since the drilled area is the weakest part of your tank the less stress the better.


----------



## Jake at River City (Jul 31, 2007)

You shouldn't have to use anything on the gaskets, but I definately sleep better at night when I use silicone. I put a liberal amount of silicone on the gasket, set it in place, hand tighten, and then do a quarter turn with channel-locks (pliers). I spread any pushed out silicone around the edge of the bulkhead with my finger (you can use a coin, back of spoon, etc.) Don't overtighten the bulkhead, it can cause the gasket to slip out.

The schedule 80 bulkheads are bullet-proof. I've found that they don't always fit standard holes drilled in factory built tanks. I suppose some planning ahead and double-checking would solve this though.


----------



## Joels fish (Nov 17, 2007)

Silicone is a lot better than a petrolium based compound, but not really all that great either. The thing is that while it gives you peace of mind it infact doesn't do anything but deminish the effectiveness of the rubber gasket. Unless otherwise specified by the manufacturer, nothing should be used except the supplied gasket. When you put the silicone on the gasket it ceases to be the gasket and the silicone is what then holds back the water. Not to mention it makes it a PITA to remove the bulkheads when and if you ever need to. As long as the surfaces are clean and in good shape you'll never need to use anything on them. I'm not trying to say it doesn't work, but it's not optimal and potentially can cause problems.


----------



## BenHugs (Jan 13, 2007)

Well I'm glad I posted this. I was thinking of using silicone grease but that seems to be a bad idea.
Thanks All :thumb:


----------



## JustPhish (Jul 16, 2007)

Vaseline may also actually help water wick by the seal. This is why you never use vaseline to lube the gasket on an underwater camera housing.

I'm confused when you say you want to seal the bulkheads. Do you mean you want to install them and use them to drain and refill the tank? Or do you mean you want to seal them off because you will not have a sump or a closed loop on your tank?

If they are grey and heavier they are probably schedule 80. If you want to employ them, make sure you keep the gasket on the side of the top of the bulkhead, opposite the nut. Tighten just past hand tight otherwise you risk breaking the bulkhead or worse the glass.

If you mean you want them sealed off then just get the approriate sized PVC to stick inside and use PVC cement to add a cap on the length of PVC. Shouldn't have to worry about any leaks.

Good luck.


----------

