Can you cut overflow bulkhead thread too much?

[NancyFish]

Received my overflow box, intimidated and excited at the same time. This thing is heavy & thick.

Did a 1600gph modular marine but in a 12” frame. Instructions claim to trim off the bulkhead thread to have room for plumbing

So while debating plumbing style, I’m just curious how much is too much to take off the thread? And also, is the internal box supposed to sit that far off the glass (I can fit a finger between it).

 

[Snoopy 67]

As far as a finger there - right now it's mounted to a piece of thin plastic. Try it on your tank.
You do need some space there for gaskets etc:. The 2 bulkheads protruding into outside box will have to be shortened to fit your plumbing. Check with whatever you are going to use there for how much to cut.

 

[BrokenReefer]

You will end up trimming them to around 1/8" past the end of the nut after it is installed.

Dry fit it together, take a silver permanent marker (that's what I used to show up on the black threads), thread the nut on the bullkhead so it's tight. Mark that point, then take it all apart and cut the bulkhead fitting, lightly sand the edges to remove any burrs.

 

[C_AWOL]

As long as the threads are intact and the nut + gaskets seat well then theres no issue cutting the bulkhead shorter.

 

[Troylee]

You will end up trimming them to around 1/8" past the end of the nut after it is installed.

Dry fit it together, take a silver permanent marker (that's what I used to show up on the black threads), thread the nut on the bullkhead so it's tight. Mark that point, then take it all apart and cut the bulkhead fitting, lightly sand the edges to remove any burrs.

This!