Hole location for Herbie for overflow's

[Palmer]

Originally Posted by The Codfather

I think a 1" bulkhead requires a 1 3/4" hole.
I might be mistaken but I think you need at least 1xdiameter from the edge.
Don't take this as law, it's just off the top of my head.

These are the bulkheads I am planning on using.

http://www.bulkreefsupply.com/store/...-x-thread.html

Looks like its greater than 1.5 " for this bulkhead its listed as 42 mm. That is the size of the diamond hole saw I ordered.

I was thinking of going at least that much out (1") just to be safe. Makes sense...

[The Codfather]

1 5/8" to 2" should work.
42mm to 50mm.

[Palmer]

So I drilled three holes in the tank tonight with the 42 mm diamond saw and wouldnt you know the 1 " bulkheads DONT fit!! It goes right up to the external thread (about a half a cm in) and just stops doesnt seem like anyway to get it through. I wrote BRS an email but honestly all the 1 " bulkheads they sell have the external thread so now I dont know what my options are...

Anyone run into this before?

The hole is pretty clean there really isnt any significant jagged edges....

Palmer

[Palmer]

It seems under the 42 " diamond saw it says its for 3/4" bulkheads. But from what I could see on the 1 " bulkhead it stated the hole size needed was 42 mm.... You just cant win sometimes... Guess I am stuck with 3/4 returns and herbie drains unless someone can think of something else I can do. You cant drill a bigger hole where the smaller one is can you? Not sure how practical that is and how to trap the water needed for the drilling...

[Lance]

I just measured a 1" bulkhead I got from J&L and it will just fit a 43mm hole.

[Lance]

Sorry about that: It is a 3/4" bulkhead, my bad.

[Palmer]

Yeah I think I am pretty much stuck with going with a smaller bulkhead... It's a 30 G frag tank to be plumbed to my main system. I may just need to limit the flow a bit to the tank....

[golf nut]

42 mil is 1.65", get a lighter schedule bulkhead.