I'll show you a fairly simple way to put one together out of easy to use plumbing parts.
Step 1: Assemble Parts and Yer Tools!
- A medium sized cooler, say 30 quart or so, it doesn't need to be huge.
- At least 20' of copper tubing. I used 1/4" ID. I would not go any larger than that. The outlet tubes in the Pepsi type kegs that this is for are about 1/4" ID, and you don't really want to be larger than that if you can help it. Being larger in diameter would give the beer time to expand on its way to your glass, resulting in a glass of foam. Boo.
- Tap w/ 4" shank. The length of the shank doesn't really matter so much, so long as it fits through the wall of the cooler.
- A short length of think-walled vinyl tubing to go from the fitting on the back of the tap to the copper tubing.
- Fittings to adapt the vinyl tubing to the copper tubing. For the copper tube fittings, I chose compression type fittings for their ease of use.
- Pipe seal (Teflon) tape.
- Not pictured: wrenches of various sizes for tightening the fittings together.
- Adapter from garden hose to nipple, same size as all the others.
- Cheap vinyl tube to fit the nipples from garden hose to inlet, for leak-testing and cleaning. The stuff I got is rated to 45psi.
- Step drill bits, or standard drill bits, in the sizes you'll need to put the holes in the cooler.
- One cat, preferably white.
- Zip ties. Lots and lots of zip ties!
I've been purposely vague on the sizes of the fittings, and the sizes of wrenches and tools for the simple reason that you may not be able to get the exact same sizes of adapters that I did.
All of the fittings were purchased at Homebrew Heaven, in Everett WA. The copper pipe was picked up at my local Lowe's, which I paid too much for, but I wanted to get all the parts all on one trip.
Step 2: Drill Out the Cooler for the Tap.
Drill out the hole with your drill bit, step bit, whatever. If you use a step bit, be sure not to go too wide on the front side, and drill again from the inside of the cooler to make the diameter the same all the way through.
Do a quick test fit to make sure that the holes are the right size.
Step 3: Drill Out the Cooler for the Inlet.
Once you get it drilled, do a quick test fit to make sure it fits in nice and easy.
Step 4: Form the Coil.
This step involves making a tighter coil out of the copper tubing, one that is as large as possible, yet still just able to fit in to the dimensions of the cooler.
I chose a coffee can to use as a form, it seemed like a pretty close fit.
Start by unwinding several feet from the coil, and holding the end next to your form, slowly start shaping the tubing around it. Be very careful and take your time, if you kink the tubing, it's done, there's no un-kinking it.
Leave several inches un-coiled on both ends, as you're use this length to attach to the inlet and tap sides.
When you get it all nice and wound up, you may want to attach Zip-ties every turn or so to have a little bit of preformed space between the coil. This should expose a little more surface area to coldness and help out a bit. Completely optional step.
Step 5: Quick Dry Run and Coil End Shaping.
Set the coil in the cooler, and bend the tubing around to fit the inlet and to a convenient place to attach the vinyl tubing from the tap.
When you bend the copper tubing this time, use something like a hairspray can for the form. Otherwise, you really, really, really need to be careful, as you're probably going to be making tighter bends that before.
Step 6: Fitting and Sealing It All Together.
First off, take the pieces that are going to go through the back of the cooler for the inlet, and give them a good stiff rubbing of cat.
That's not right at all.
Use the pipe sealing tape, that should much better.
Give it a couple full turns of the sealing tape and thread them together through the cooler.
When you get it tight, make sure that it's really tight. Not to the point of stripping the threads, or giving yourself a hernia, but really tight.
Next, assemble the fittings for the tap side in the same fashion, but don't put the compression fitting on the copper tubing just yet.
Push the vinyl tubing on to the nipple of the adapter and the tap, making sure to get them on as far as possible, at least past the third rib on both.
Now for the compression fittings.
You'll find a nut, a sleeve, and the piece that they both fit into. Slide the nut on the tubing, the sleeve after that, and then slip the tubing into the threaded piece. Slide up the sleeve, the nut, and hand tighten the nut.
With the nut hand tightened, take a wrench and tighten it down some more, about a full turn or so.
Grab your wrenches, garden hose adapter and cheap vinyl tubing, and go outside and lead test it!
Step 7: Leak Testing.
Hook it up to your garden hose, open the tap, and barely, just barely turn the water on. I'm talking less than a tenth of a turn. Just barely. That's more than enough pressure. You only want to give it a couple psi for now.
Start looking over your fittings and make sure they're still dry.
If any of the fittings leak, crank 'em down until they stop. But, with the compression fittings, be a little careful with them. You can over-tighten them and split the copper. Just tighten those down about a quarter turn at a time.
To give the system a little more pressure to deal with, close the tap for a few seconds at a time to let it build up some. Don't leave it closed too long though, you can get well over 50psi of pressure off city pressurized water.
Once everything's good and tight, let the water run through for a while to clean it out.
You want to run through a good cleaner that is safe for food apparatus. Check with a homebrew store in your area for the best way to do, as there are more than one.
Last step, pack that sucker up full with ice and just a little water, and run your beer through!
As for how to attach it to your keg, match the type of fitting on the keg and use some thick wall vinyl tubing to connect them together. Most pepsi type kegs use a ball-lock type connection.
You'll have to fiddle with how much pressure to give the beer, try 11-15 psi to start. Different beer types and keg temps will take different temps to get the pour with the right amount of head for your taste.
And, don't forget to clean it after you use it!
There you go, happy beer drinking!