Silicone hold to bulkhead though overflow?

[SkinnyPete]

I know...what the heck am I talking about?

Well, I bought a used 125RR a few months ago, only setting up now. There is a bulkhead drilled THROUGH the overflow (see another post with pics here... http://www.aquariumadvice.com/forums/showthread.php?t=98101 )

The guy I bought it from says he was using it as a closed loop. I didn't really think of it too much since he was selling for a good price and I saw it set-up...no leaks. Well, now that I'm setting up I'm realizing that I should have thought this through and passed on the tank. It's a real pain.

Eventually, I decided against using the bulkhead because it was more trouble than it was worth. So, I want to just block it off tightly. I want to make sure it is sealed so that if there is any plumbing leaks, my tank will only drain the overflow and not the entire tank. If this bulkhead leaks through the overflow, since it is at the bottom of the tank, and there is a leak in my plumbing...the tank will drain.

So, the problem - I plugged the bulkhead up using glued pvc, no problem...BUT, when I screw the bulkhead on the washer on the bulkhead does not seal because the overflow itself is curved, so it doesn't lie snug against the overflow wall. I was thinking of just using silicone to plug it up. Will silicone bind to a bulkhead and the plastic of the overflow well enough to depend on it? Do I use silicone in place of the washer or WITH the washer?

Any help would be appreciated. I can't start this tank until this silly bulkhead through the overflow is fixed.

Thanks.

- Skins

 

[ellisz]

Silicone around the bulkhead should work. Silicone holds the walls of the tank together so I would say you could depend on it.

Did the guy say how he plumbed the closed loop? He would have used a bulkhead on the closed loop as well.

 

[SkinnyPete]

Yes, he used this bulkhead as a return. So the return came up through the regular return bulkhead inside the overflow, then he used pvc to bring it through this bulkhead into the tank where he ran a series of pvc pipes through his rock.

I just don't like the idea of this bulkhead at all. I did try the silicone and it appears to have worked. Since the overflow is plastic and the gasket is rubber, I wasn't sure if it would hold like it does to glass. But, it seems fine.

Thanks.

 

[ellisz]

I have a bulkhead I widened and I had some sealing issues. I used silicone to seal it up.