Have a 4 hole enamelled cast iron sink. Holes currently filled by 3 hole faucet plus separate sprayer. Need to install an air gap for dishwasher.

Limitations:

Cannot simply "loop" d/w discharge line in place of air gap due to local codes. Not practical to replace sink as it is tiled in. Want to keep sprayer.

Solutions?

1. Replace faucet with one that has sprayer built-in, freeing 4th hole for air gap. Probably the most sensible solution... except for the fact that we really like the existing faucet design. (otherwise I'd just go buy a new faucet and wouldn't be posting this to begin with! ) Will probably end up "settling" for this solution if no other solution presents itself.

2. Drill a new 5th hole for air gap. What tools/techniques would be required to successfully drill enamelled cast iron? DIY-able?

3. Does there exist an air gap design that allows the sprayer supply tube to "pass-through" it, like some faucet designs incorporate? So that both could occupy the same existing 4th hole?

Any comments on 2 or 3? Or other thoughts? Thanks!

 

Purchase a good (not cheapie) hole saw and go with #2. Make sure the hole saw is for metal. Only other thing you need is a drill. Rental places are also an option if you think it is a one time drilling job. Good luck.