Leaking Bulkhead: Aquamend and/or Silicone?

[Jive Turkey]

I have a very slight leak with a bulkhead on my tank, about 1 drip every minute. Its in the middle of the back pane of glass acting as a closed loop drain. It'll require 60 gallons to be removed if I were to saw the BH off the manifold and replace it. I want to find a solution that doesn't require me to do this.
The leak is finding a way around the flat O-rind AND is making it way thru the threads under the ring that screws on/off. I have some of Home Depot's Aquamend epoxy dryed on from last night, and the leak has stopped, for now.... I though these were pretty nice, black 1.5" bulkheads from www.customaquatic.com.

I am thinking of slapping some silicone glue over it, but I am wary of a chemical reaction between the silicone and the Aquamend that may weaken the epoxy. (think of unbaked clay crumbling off).

Has anybody tried this or heard anything about a combo of these two adhesives? RC is down so I'm at a disadvantage tonight.

Thx, Joe

[manderson0805]

Did you use silicone the first time you put the bulkheads on?? If not, you can try to cover it..it may work, it may not. I would think that if it didn't work you'd know within the first 12 to 24 hours.

[clyde]

I would swap bulkhead, easier IME

do a waterchange at the same time while you're at it

I did a silcone thing on my bulkhead - it made the leak WORSE, I suspect the rubber o-ring had an reaction to the silcione..

now I just swap em, as sometimes its rather hard getting silicone to dry while theres pressure going at it (dripping/leaking or whatever)

[Jive Turkey]

Mike, Clyde was right about the silicone affecting the rubber O-ring. Apparently it makes the rubber hard and causes it to crack.

Clyde, sawing the BH off will be a MAJOR pain in the ass. It's the last option. In this new 120g setup, I have already had a cracked bulkhead that is supporting a closed loop sprayrack at the bottom, that required the tank be broken down last week. Just put it back together a few days ago, and a leak starts after a week-long FW test, and a week of the SW setup before the crack.

As for the silicone over the leak, I have put the Aquamend over it first because it can be applied to slow leaks and is meant to adhere to wet surfaces. It's meant for boats afterall, among others. The silicone will go over it maybe, for peace of mind. I am just worried about a reaction between the two that degrades the main bond, the Aquamend.

This is my first time doing a complicated plumbing setup with bulkheads and PVC. Its a double closed loop, single return system with a tank room behind it.

[David Grigor]

Can you take the back nut off without having to saw the manifold. If so, add a new gasket on the back side or loosen it enough to get a good bead of silicone all the way around the nut and tighten it back.....

[Jive Turkey]

Thanks David, thats some good advice. I am not able to get the nut off, but can back it out about an inch. I am going to go do that right now...

Joe