How do you use a bulkhead properly?

After I install bulkheads in my tank I notice they leak, so the logical thought would be to tighten them down more right? Well in doing so I have cracked two tanks now. Is there anyway to tighten them less without them leaking? When using 20-30 gallon tanks the tanks crack so easily. I have to get a new one again and drill and install the bulkhead. Can someone please give me advice on how to tighten bulkheads enough to where they won't leak and won't crack the glass. Im getting so frustrated. :-/

 

First make sure the rubber gasket is on the inside of the tank, and then hand tighten, then do another quarter to half turn with wrench and you should be good to go

 

I will try it out, thanks/

 

Ditto that. And I would only add for clarity that the flange goes on the inside too and the nut on the outside.

 

dont feel to bad i just cracked a 120 gallon tank like that. this time i will hand tighten and then i will silicone the inside of the bulkhead.

 

Here is the contents of a Sticky I have done that is posted on several Reef Forums:

Installing Bulkhead Tips

Bulkhead tips:

1. Always install bulkheads clean and dry, no silicone's, teflons or thread lubricants. Silicone's 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 time and creates a perfect seal without any help.

2. Before installing the bulkhead take a few minutes using a jewelers file, nail file or pocket knife and clean any excess flashing off both the male and female threads and from the flat gasket mating surfaces. This is a common source of leaks.

3. Always install the gasket on the flange side of the bulkhead, never on the nut side, regardless if its inside or outside the tank. Installing the gasket next to the nut will lead to leaks. Hand tighten only with maybe 1/4 to 1/2 turn additional, no more.

4. When using threaded bulkheads, again clean the excess flashing from the threads and valleys and use a small amount of teflon tape or better yet the stick or crayon type of thread lubricant designed specifically for PVC treads. These can be found at Lowes, HD, Ace and all hardware stores under names like Laco, Permatex and others.

I use this one and have since the 1980's with great success.
LA-CO: Product Detail - PLASTO-JOINT STIK® - Plastic Thread Sealant
It stays pliable forever and does not tear or roll out of the threads like teflon tape. My swimming pool plumbing up to 2" was all installed with this in 1983, outside in Phoenix AZ and its still pliable to this day!

5. Never support any pumps or piping from a bulkhead, always use supports so weight is not on a bulkhead and gasket causing differential stresses on the mating surfaces.

6. Never screw anything to the external threads of a bulkhead, these are not standard tapered pipe threads and will leak. They are there to screw the nut on is all and are not normally even a standard diameter like 1" etc.

​

Read more: Installing Bulkhead Tips


One thing I cannot stress enough is take the time to clean the molding lines and excess flashing off the flat surfaces and from the threads, wate rlike to seep or travel though those voids and will drip forever. A small pocketknife and a nail file work perfectly.

 

I am having no luck finding a place to purchase the Plasto-Joint Stik - Do you have a source?

 

Ace or True Value Hardware both have them around here as does Home Depot. Its usually where the teflon tape and paste are for natural gas or LP in the plumbing aisle. Permatex makes one as does IPS/Weld On.
I have one from Ace Hardware with their own store brand on it but it looks just like the Laco product.

 

Thanks!!

 

agreed. rubber gasket and tighten just beyond hand tight....shouldnt leak.