I use a half barrel for my mash tun and I used the piece I cut out of the top of the keg as the false bottom. I removed the stem and sliced the neck down below the ears, used a SS flat washer that fit inside, put in a thru wall fitting to a chuck of tubing to the valve in the side of the keg. I had to use a nipple in the thru wall fitting to extend the pick up lower for less dead space. Anyway I hope that makes sense with no pictures.