What size bulkhead do I need??

[Mester320]

I have attached a picture, the holes measure exactly 1 3/4 inch. So I need to know what size I need and should I do schedule 40 or 80.

Also if you can see in the pic it is chipped away some on the inside, will this be ok?

 

[Hitman]

The chip should be ok. Here’s a few charts on hole size compared to bulkhead sizing. So in a 1-3/4 inch hole you would use a 1” bulkhead in a schedule 40 or a 3/4” bulkhead in a schedule 80.