[bob22]

How big a hole? Picture available? I doubt anything you use will last; perhaps JB Weld (I've never used it but people swear it works).

 

[bob22]

What code? If it is your house, do what you want with it. Didn't you just buy it?
If you are selling, who is going to buy a house with a hole or patch in the kitchen sink?

 

[bob22]

Sounds good! At worst, you might have to shell out some $s for a new sink; look at it as an early investment with a long-term benefit.
My guess is they won't notice especially if it doesn't leak.
Good luck!