First of all, thank you to Datsun1500, NYG95GA and Toyman01 for pitching in with suggestions. Here's how it went....
The problem was how to enlarge a 1/2" center mounting hole in a porcelain bathroom sink to 1" so I could mount a newer-style faucet assembly. The pop-up actuator rod did not clear the original 1/2" hole.
I spoke to the owner's daughter at my local Tool Shack. She's almost as knowledgeable as her father so she gave me the skinny on what I needed to succeed.
NYG95GA, it turns out your suggestion of a carbide-tipped masonry bit would result in chipping the porcelain so I opted for Toyman01's idea to use a diamond-tipped hole saw. Using plenty of water as a lubricant (as per instructions) with a relatively slow rpm, I let the weight of the drill and the cutter do their thing. Every 30 seconds, I dunked the bit into a glass of water. After 10 minutes of patient cutting, the saw punched through the other side clean as a whistle. The hole looks like a factory job.
Now my wife is happy and the whole adventure ran a mere 20 bucks so thanks again to everyone who provided ideas for updating this sink and keeping our recession remodel "grassroots."
Now everybody knows it can be done. There's a handy bunch of folks hanging around here.
Jerry
