I know that this is an old thread, but I recently purchased one of these 100 quart / 25 gallon pots from this eBay vendor. Very nice pot! The thing is a monster compared to my 15 gallon keggle, of course. $125 (w/ shipping) pot plus $95 (w/ shipping) spent on a 3-piece valve, a sight glass and a weldless bulkhead / SS dip tube from Brewhardware and I had me a nice new 25 gallon boil kettle. Now to drill the three holes needed to install the valve and sight glass...
HOLY CRAP WAS THIS THING HARD TO DRILL THROUGH! That thing I said about being worried about how thin this stainless steel was? Yeah. That's not a worry in the slightest now.
I've drilled a few holes in my SS kegs in the past, and they were pretty darn easy. But THIS pot...oh man, it did not want to give up the fight! I started out with some hardened steel drill bits to make pilot holes for my step bit, some vegetable oil for lubrication and used a variable speed drill and went slow, the same thing I used on my previous ones. I snapped three bits before I gave up and went to the hardware store and bought some cobalt steel bits and some better cutting oil. And even the cobalt steel bits took freaking FOREVER to get through! Maybe it was because Menard's sold some cheap Chinese knock-off cobalt steel bits, I don't know.
Anyway, I did finally get the pilot holes drilled, and then used the step bit to finish the holes. Thankfully the step bit didn't have to struggle much to get the holes big enough.
A couple of minutes with a round metal file, and voila, three very nice holes ready for use.
We calibrated the sight glass and found out that the pot holds about 26 gallons, not 25. Bonus!