Last year I had this idea to a build a compact mash tun with the capability to recirculate and heat like a RIMS system. Well after going back to the drawing board numerous times, this is what I finally came up with. The first thing I did was have a stainless steel filter bucket built to place inside of the cooler. After that I built the heater tube out of stainless pipe and a brew heater that I got from my local brew shop. I bought a Sous Vide temp controller on ebay that has the capability to do up to 8 phases so I can do an automated step mash. I'm in the process of building a raised round platform to mount the Chugger pump to so I can sit the cooler on top of the platform, but for now I have the pump bolted to a piece of pine. Last weekend was the first time that I have used the whole system together including the heater pipe. I did a Hefeweizen doing a 90 minute automated 4 step mash. All in all I am very happy with this set up and I hit 85% efficiency on my first try. I'm sure there will be some more tweaking that I will do but at least I have a good start. Experimenting and building equipment is why I love the hobby of beer brewing so I thought I would share my ideas for others to improve upon!
Here is a YouTube video of my system in action http://www.youtube.com/watch?v=s7Uu6lq_gLs&feature=youtu.be
Here is a YouTube video of my system in action http://www.youtube.com/watch?v=s7Uu6lq_gLs&feature=youtu.be