Its still a work in progress....
I'll have pictures soon, Its full of fermenting goodness at the moment.
I used a 15 gallon Sanke Keg. I removed the stock valve and stem.
Install lid on bottom for easy cleaning & access:
I flipped it upside down and cut a whole the same size as a corny keg lid.
On the test keg I used a dremel and a jigsaw with a metal blade. It came out "ok". On the second keg I only used the dremel with a reinforced cut off wheel. It took a bit longer, but came out much nicer.
I cleaned the keg out really well (!*NASTY*!), and installed Corny lid in the bottom of the Sanke.
I temporarily reinstalled the stock stem and pressure tested for leaks. Tested with and without pressure. Passed tests, removed stem.
Sanitized. (wee-bit heavy to empty) I’ll have to give that some more thought.
Brewed 12 gallons of porter, chilled, and transferred into sanitized Sanke fermenter. Pitched yeast.
Stuck a sanatized #10 rubber stopper with a blow off tube in the top of the Sanke keg (where the stock valve and shaft once resided.)
It is fermenting nicely this morning!
I don’t know if I want to attempt to fabricate a racking arm or not.
Originally, I just wanted to be able to ferment larger volumes at once.
I still plan to build a second one for the secondary.
I would like to figure out how to install the corny keg tubes and poppets onto a sanke. It would be nice to use one standard connector (Like QD's) for everything transfer under pressure, filter, serve, ect.
I'll keep playing with it.
edit note: the stopper was a #10, not a #15 ;-)