Questions about bulkheads Please!

[Pman]

I am hoping I can get some input from anybody and everybody about the way your drain bulkheads are configured. First of all what size are your drain bulkheads and how do you hook them up at the bottom of your tank , meaning is it a 1 1/4 fitting you use to thread on the outside of your 1 inch bulkhead or do you prefer a 1 inch fitting threaded into your 1 inch bulkhead? I would really appreciate all your input because I am using this data to make my upcoming tank manufacturing company pleasing to all! Thank you !

[RWD]

Pman,
The threaded part on the OUTSIDE of the fitting is used to hold the fitting in place. A large nut goes on the fitting and compresses the rubber seal against the tank. The INSIDE of the fitting can be either threaded or a slip joint. The slip joint type is if you intend to glue it permanently to the plumbing. I use both types of bulkhead fittings, slip and threaded. A 1" fitting usually requires a 1-3/4" hole to be drilled.