what size bulkhead?

it Appears that my drilled hole is 1 7/8. what size bulk head do i need?

 

I believe the "general rule" is that the inner diameter of the hole is 3/4" larger than the inner diameter of the bulkhead.

 

do i need to replace the bulkhead/overflow if i want to put connect a box to the bulkhead? I was thinking of ordering a kit from gl*******s.com something like this

and i just dont know what size bulkhead i need?
Here are some pics of what is currently in my drilled hole overflow.....



This is the size of the PVC elbow that slips inside the front of the bulk head. The PVC elbow is Lasco brand and says 1" on it?
This is some pics of whats installed on the tank



Help it appears that the drilled hole is around 1 7/8 inches?

 

Interesting setup. that is some sort of reducing street elbow. I would say you have a 1 1/4" bulkhead. measure the inside of the bulkhead and you will get the exact size on it.

Glass holes makes a FINE product.

 

I gave you the answer already. But since you're pvc elbow is 1" you need a 1" bulkhead.

 

My bad. I still wasnt for sure which size bulk head i needed:-/

 

Don't know if you need it but here is a Bulkhead / Bulkhead hole chart
that I found online.

And if you are going to use gla$$holes you can't use the "s" LOL, isnt
that just the stupidest thing you ever saw!

1/2” ABS Bulkhead - 27mm/1.06 (Installation Hole Size) 1 1/4"
3/4” ABS Bulkhead - 34mm/1.33" (Installation Hole Size) 1 3/8"
1” ABS Bulkhead - 42mm/1.65" (Installation Hole Size) 1 3/4"
1 1/2” ABS Bulkhead - 59mm/2.32" (Installation Hole Size) 2 3/8"
2” ABS Bulkhead - 72mm/2.83" (Installation Hole Size) 3"


3/4” SCH 80 Bulkhead - 41mm/1.61" (Installation hole size) 1 3/4"
1” SCH 80 Bulkhead - 48mm/1.88" (Installation hole size) 2"
1.5” SCH 80 Bulkhead - 64mm/2.51" (Installation hole size) 2 5/8"
2” SCH 80 Bulkhead - 81mm/3.18" (Installation hole size) 3 1/4

 

cool. gazog

 

All those millimeter sized drill bits can be found on EBAY if needed for really cheap. Thats where I get mine, I paid 4 bucks for a bit to drill 42MM and 59mm holes and used them to drill approximately 10 holes each for different people.

Only problem is if you order them from there make sure you are not in a hurry to receive them because it takes about 10 to 12 days.

 

thanks this helped me find what I need!