View Full Version : Bulkheads which side?

04-13-2004, 11:58 AM
Ok I am drilling my tanks and W/D filters for bulkheads. Which side should the gasket go on, the tank side or outside? I only have one gasket for each bulkhead.

Any tips on installation would be nice. The first couple I put in seem to be leaking.

04-13-2004, 03:25 PM
Intially, I have been putting them on the outside of the tank however I would also be getting leakage, particularly from the threads despite telfon tape. Just recently I have been putting the gaskets on the inside and no leakage. The only concern would be the gasket material and if any seapage into the water.

What size of bulkhead?

04-13-2004, 03:44 PM
They are the 3/4" and 1" bulkheads. They both are the same outside diameter just different size holes for the pipe to fit. One side is slip the other side if FPT.

04-13-2004, 04:40 PM
The bulkhead I bought from Jehmco says to intall gasket inside. I have no leaks.


04-13-2004, 06:37 PM
frequently, if there is only one gasket, it goes on the side of the glass exposed to the water. (Inside)

04-13-2004, 07:12 PM
I have found some rubber gaskets at home depot that work really good. I'll try and take a pic of one tonight. It really fits snug around the male thread and is around 1/2" wide. ;) Inside seems to be the answer! ;D

04-13-2004, 07:17 PM
And in the event of leaks or insecurity, silicone makes everything leakproof and watertight

04-13-2004, 09:39 PM
Thanks for the responses! Inside they go with a bead of silicone. Roncra please post a pic of those gaskets. I would like to pick some up while I am at the depot.

04-14-2004, 02:41 AM
If you can't find some gasket that fits you can cut your own. They sell the 8" square of rubber sheet for customized gasket.


04-14-2004, 04:03 AM
You could also pick up some 1/8 inch thick gasket material. Used on flanges,etc ... food grade quality. will not contaminate the water. The gasket material is thick enough to be reuseable.
Any Acklands, [etc.], industrial place sells the stuff. Comes in sheets or rolls. Easy to make your own . cuts with sissors. or Just use an inexpensive wood hole saw ... the type you buy for a couple of $.$$.... usually 6 different sizes come with the unit. AND drill your own gaskets. This stuff is tough!!
A thin bead of silicone will make a 100% leak-proof seal.

I just got my 6 new 55 gallon tanks; all are drilled, I will be double gasketing the bulkhead filltings [ inside and outside ] .... [I hate any kinda leak]! lol....


This is the same material I use on the peat bomb ... Unbolting the top - on and off and the gasket material is like new.

04-14-2004, 07:38 AM
Gasket on the inside.....
if you think about it.....a gasket on the outside does nothing....if the water makes it that far, it's going to run down the threads....not through the nut..... ;D
a bead of silicne is a good insurance policy....again....on the inside

04-14-2004, 10:22 AM
Wow! Some very good suggestions especially about making your own gaskets! ;)

I double checked my gaskets and they are on the outside of the tank! :o LOL! No leaks with these gaskets! ;)

04-14-2004, 10:30 AM
This is on the 250G water storage tank! Again, on the outside! The gasket kind of double seals; between the tank and bulkhead fitting, between the threads and bulkhead fitting!

04-14-2004, 10:31 AM
This is the bulkhead on my 65G tank! Again, double sealed and will not leak! ;) I love how wide these gaskets are. They fit very snug around the threads of a 1" male and are wide enough to seal the threaded part also!

04-14-2004, 11:58 AM
what are you using on the inside....
that is not a "standard bulkhead"

04-14-2004, 02:55 PM
Can you expand on 'standard bulkhead'?! LOL! The fittings Im using for my bulkheads are Home Depot 1" male threaded-Slip and 1" female threaded - Slip. ;)

Here is a pic of the inside!

04-15-2004, 10:48 PM
I wouldn't think you would have enough lip on the inside to get a good seal. Are you caulking the inside?

04-16-2004, 10:04 AM
Its not a flat gasket rather the gasket has a flange on the front. I make sure that this is against the tank. The back of the gasket is flat and the 1" bulkhead fitting tightens to seal. I do not use anything else on the inside! ;)