All the sharing of knowledge and inspirational builds have been instrumental in the building of my eHERMS brewery. I thought I'd contribute a little something - my element housing.
I think it's a melange of ideas posted around this site. I couldn't find something exactly like it on HBT, so I wanted to add it to the discussion. I wanted something that was cheap, very reliably water-resistant, doesn't rely on JB weld or other insulating epoxies, allows easy access to the element for replacement/cleaning, and has reliable grounding to the keg without additional wires hanging out of the box/cable. I had a buddy who could do the welding for free (not the prettiest welds I've seen, but they get the job done), so a welded application was appealing, and seemed more likely to be leak-proof.
I also had a few of these sitting around from a stainless bulk buy I got on ebay:
A 1/2" NPT 3 piece union conveniently uses 1" NPS threads (I think) to join the pieces of the union. This means the standard heating elements screw into it perfectly. This exact application would work if you used the (more common) 1" NPS locknuts sold on the various brew hardware sites.
Here's what I settled on. See photos with captions here:
1) Used a greenlee 1" conduit punch (i.e from a #735 knockout set) to make a hole in my 15.5 sanke keg.
2) Disassembled the 1/2" NPT union, used the middle piece (as mentioned above, threads work perfectly for the 1" NPS element.
3) Used an angle grinder to cut off the threaded portions of a 2" NPT pipe nipple. (http://www.amazon.com/dp/B003JQJOKY/ref=biss_dp_t_asn). You can contour the cut a bit so it sits flush with the keg
4) Welded the union nut onto the keg, then welded the cut off pipe nipple threads around that.
5) Cut a 2.5" hole into the back of a metallic waterproof 2 gang outlet box with 3/4" NPT threaded inputs.
6) Install a 3/4" strain relief onto 10/3 wire, then screw the strain relief into the outlet box.
7) Slide the outlet box around the 2" pipe nipple, then secure with a 2" conduit lock nut
8) Connect wires to element
9) Install weatherproof outlet box cover, and you're done!
Hopefully that makes sense. What do you all think? Is this overly complicated? Thanks again to all for your teaching and inspiration over the years.