Just built this 48qt Rubbermaid Cooler MLT using CPVC and CPVC Cement. Had the cooler laying around already and spent ~$20 on the rest of the supplies. Can't wait to try it out, I have some grain on order. This will be my first attempt at all grain and I'm excited. This stuff was all built with the help of HBT ideas.
Built using 1/2" CPVC, I haven't put the slits on the bottom yet, but will do that tomorrow using a dremel and cut-off wheel. The manifold is pretty solid in there, shouldn't move around much if at all. I didn't cement the manifold connections together so I can disassemble for easy cleaning.
I used CPVC cement to seal up the hole on the cooler. A 1/2" cpvc coupler fit perfectly inside the factory hole and a bit of cement secured and sealed it right up. I'm going to put some epoxy from the valve to the cooler just to strengthen it up a bit.
I will be modifying this tomorrow for use as a Grain Mill. It's a pasta roller I picked up for $14 from Michael's (found a 40% off coupon online). It turns perfectly with my cordless drill with a 3/8" paddle type drill bit. Just need to gouge up the rollers and fab up a hopper. I think it'll work well.