In spite of what you might have read on Hackaday, the keg kettles (typically called keggles in the homebrewing world) have not been chromed. Instead, that lovely shine was acheived nothing more than elbow grease and some quality time with a angle grinder.
I will take almost no credit for this work. I did a final pass with a buffing wheel and some hand polishing, but the brunt of the labor was done by the friendly marketing guy responsible for this project. I pointed him to a pretty good write-up of the keg polishing process and promptly left town for a week and a half. It was definitely not my intent to slyly coearce him into polishing the kegs for me, but it definitely worked out quite nicely. You can find the instructions here. I won't comment on how many hours he spent working on it, but I can share the before and after pics that he sent out.
The shiny kettles don't really make any better beer, but they're definitely pretty! The other interesting thing about the keggles is the soldered fittings that I have spread throughout each of them. Homebrewtalk.com has some really good how-to discussions about soldering stainless, but there are really 3 important things that I'd like to point out.
First, use good flux. I had no trouble getting plumbing solder to flow (just make sure that it's the lead-free stuff that's suitable for drinking water). I picked up a propane torch kit and the solder up at Home Depot or Lowes, but the fancier flux really makes a huge difference.
Second key is to make sure that you prep the surfaces properly. You have to make sure that they're degreased, and scuffed up with a fine grit sand paper. That goes for the keg wall as well as the fitting that you're planning on soldering in. If you screw this up, you're likely to not get a good junction. As long as you get both parts hot enough, you should get the solder to wet the surfaces properly. If you don't get a good seal, it's not a big deal to get it hot again and try to make the solder run. If it still doesn't flow, it isn't tough to heat it up, pop the fitting out with a hammer, re-prep the surfaces and start it again.
I think the biggest thing though was the use of a dimpling tool. There's a really good discussion in the soldering thread that I liked earlier, but I'll keep you from needing to search through all of the pages. I follow this parts list and these instructions to put together a tool that pulls the fitting through a slightly undersized hole. It makes a really nice mechanical fit between the keg and the coupling and also gives a nice valley for the solder to flow into.
For most of the ports, I used normal stainless 1/2" NTP threaded couplings. On some of the ports that I knew would only have something screwed in from one side (like the thermometer ports) I used half couplings because they were a little shorter and a little cheaper. If you use these half couplings though, remember to put them in the right way. The tapered fittings will only let you screw in something from one side. I learned that lesson the hard way. For the water heater elements, I used a 1" nut on the HLT and a 1" welding spud on the boil kettle. The spud was pretty cool, but because it was on the outside of a curved vessel, I had a little more trouble getting the solder to flow than I had hoped. I ended up with a little leak and decided to use a little JBWeld on it anyway.
Add some valves, add a sight glass and an old fashioned analog thermometer on the boil kettle, add a heat exchanger and add some various other fittings here and there and you've got my setup replicated. Simple as 1,2,3,4,5,6... In the next two pictures you can see the built-in immersion chiller in my boil kettle and the port and silicone tubing that I use to create good whirlpool action while the beer is cooling.
In the bottom of the kettle, I have one of these guys soldered to my copper pickup tube:
There's a lot of stuff going on with the electric heating element, the pickup tube, the wort chiller and the screen all in the bottom of the pot.
I've gotten a lot of questions recently about scorching. The short answer is that I get basically none, definitely no more than I got on the bottom of the pot when I was using a propane element. It's definitely a little harder to clean off the element than it is the bottom of a pot, but a good soak in warm OxyClean does wonders.