Please help with installing bulkheads!

[elmatth1]

I recently bought a 100 gallon stock tank to use as a sump in my basement and drilled three holes in the tank for 1" bulkheads. I'm using the holes for the return pump, the protein skimmer pump, and a drain for easy water changes. My problem is, when I filled up the stock tank for the first time, the two bulkheads for the return pump and skimmer pump leak. I don't know if I just don't know how to install a bulkhead or what. Do I put the rubber washer on the inside or outside of the stock tank? Also, how much do I tighten them down? Seems that no matter how tight I got it from hand tightening to using a wrench, they're still leaking! Now I've cracked them both and have to start with new ones! Please help!!

[Honigbiene]

Inside the tank-
Just a little more than hand tight should be enough-
You cracked them? That`s way to tight where are you putting the washer at?
Make sure there is no debris around the bulkhead when installing them-

[eastcoaster1]

The rubber gasket goes against the flange (which is the circle of plastic on the non threaded end of the bulkhead).
It doesn't matter whether the flange is on the inside or outside of the tank as long as the gasket is in the correct location.
If the tank is round you might not be able to get a good seal with stock gasket because it might be too thin to fill in the gap. I'm not sure what you would do in that case, but I'm sure someone else can help you out if that's the case.

[elmatth1]

I put the washer on the outside of the tank against the bulkhead flange. I first only tightened the bulkehead nut down by hand, then 1/2 turn or so. After it started leaking then I figured it wasn't tight enough, so naturally, I started tightening.... and then tightened some more... and then it cracked! This time, I thought I better enlist the help of some fellow reefers. I wonder why they don't give you two rubber washer with the bulkheads... one for the inside and one for the outside... oh well. The stock tank sides are flat, but angled inward from top to bottom slightly, so I wouldn't think that would matter much.

[eastcoaster1]

When you have the bulkhead installed does it stick out of the side of the tank, or does it protude into the tank?

[elmatth1]

I've got them installed so they stick out into the tank with the flange on the outside of the tank

[elmatth1]

Do you think I'd be better off trying to find some more rubber washers and having one on the inside and one on the outside... seems to me that way would work best. Does anyone sell those rubber washers by themselves or do you have to buy the whole bulkhead?

[eastcoaster1]

The question on how to install bulkheads comes up alot, that's why I asked how you had them setup. From the sounds of it you have the gasket in the right location.
You could try reversing it so that the long end stick out of the side. Some folks will swear that it has to be done that way, but it really shouldn't matter as long as the gasket is between the tank wall that the flange. If your clamping down on the gasket with the nut, then it will definetly leak, which is why they don't give you two gaskets.
I'd image you could silicone them in place. I'm not sure the silicone would stick to the stock tank, but I bet it would make a good seal.