Can a bulkhead safely be installed upside down (with the threaded end underwater in the overflow)? I am setting up another tank and don't have any room to hard plumb the drain to the sump. I am using a Herbie overflow and need to install a valve but I am about an inch short. If I reversed the bulkhead, it would give me the room I needed. What if I used a gasket on both sides....would that help or am I risking a leak?
You can use a bulkhead in the way you described. The gasket always goes on the flange side of the bulkhead never on the nut side. I wouldn't reccomend 2 gaskets as it can cause the bulkhead not to seat correctly and leak.
Yes. You can also take the gaskets out of the situation and just use building grade silicone and just silicone them in. Not the marine land silicone that's only meant for seam repair. Put enough silicone on inside of the flange to fill the void between the threaded stem and squirts out the back side so a couple threads on the nut has silicone in them. Let it cure for 24 hours abd you'll have s seal so tight you'll have to use pliers to get that bulkhead out. I've done this over 20 times with bulkheads up to 1.5" none have ever leaked. Someone that doesn't know what their talking about is gonna say you can't do that but they have never done it themselves or used marineland silicone. The stuff I use which is meant to hold the panes of you glass together will be 10x more reliable and water tight then then those stinking gaskets. I'll give a Person my 400g system if someone says not to do this, if they find my stuff doesn't create a seal so strong you gotta break the bulkhead to get it off. That's how confident I am in siliconing the bulkhead in.
Yes but never never ever use silicone or sealants. Always install the gasket clean and dry and on the flange side, regardless if the flange is inside or outside.
Read my Bulkhead Tips sticky post for lots more information and tips.
I am setting up a 180 gal glass tank with 3 overflows. The tank is 29 in high so no way to hold the water side when tightening.
I guess I will have to arrange it over the holes with a grabber, then may be able to apply silicone & tighten the underside.
Any tips appreciated.
