could I add a ball valve to my brew kettle?

I have an 8-gallon Polarware brew kettle that I use for heating mash water and boiling. It would be a lot easier for me to do the transfers if it had a valve and hose coming out of the bottom. Could I just drill a hole in the sidewall and insert a brass valve? Can I just use a regular brad-point drill bit? Are there some high-temperature washers/ o-rings that I could use to seal it up watertight?

The link stated above is where I got all my bulkheads, quick disconnects, etc. They are great! However, I would suggest using a 7/8" step drill bit. It is a much cleaner cut.

bargainfittings also sells step bits. Never purchased from them but they end up only a few bucks more than sourcing everything locally for me.

After running all over town last time I built a bulkhead, sure seems worth it.

sweet - I already have a step drill bit

do I have to add any washers or o-rings to make a watertight connection?

is this the one I want?
http://www.bargainfittings.com/index.php?route=product/product&path=44_35_46&product_id=91

Check out the "weldless" bulkhead kits on the link above to get an idea of what items you'll need to make it leak-less without welding.

Having done this recently allow me to offer some wisdom. It will be best if you have a 1/2 high torque drill motor that is variable speed. Cutting fluid is a must. Stainless has a tendency to harden if it heats up, therefore slow speed with cutting fluid is essential. Be it that a kettle is thinner than a keg you might get through it before the the steel tempers if your heat gets out of control. If it glows red you're screwed you'll have to grind out the hole with a die grinder. Ask me how I know this.

i would suggest you get this kit with and get an extra shim washer. my kit fits a little loose. i got the $4 brass valve and bought a barbed fitting at the local hardware store because i use 3/8" hose and the website only sells 1/2". http://www.bargainfittings.com/index.php?route=product/product&path=44_35_46&product_id=91

here's my thread about needing a downspout to go with the ball valve and not knowing it
https://www.homebrewtalk.com/f14/how-do-i-install-weldless-bulkhead-212325/