Wunderbar Soda Gun
Making your own carbonated softdrinks is easy & cheap
Tired of paying more for your refreshments than gasoline? I certainly was, and with a little help from eBay and a few kind sellers, I was able to obtain the parts, design and build a refrigerated 10-Button Wunderbar Soda Gun system, integrated into my kitchen counter/cabinet. Note that all modern systems are of the "Post Mix" type where the syrup and water are combined at the tap/gun. "Pre Mix" is all but dead and horribly inefficient...so forget about it.
Basically, the one overriding consideration for proper soda dispensing is COOLING. The amount of carbonation that water will hold dissolved is proportional to water temperature. Colder equals more and longer, and well carbonationated water is quite essential for good tasting soda.
Many commercial setups utilize a 'cold plate' heat exchanger. This is basically a block of aluminum with channels for fluid to flow through, submerged in ice. In a residental configuration, it's unlikely that melting a bunch of ice to cool your water/syrup lines is desirable. So, you basically have one good option...a dedicated refrigeration system that maintains a small 'ice-bank' that your soda and syrup lines run through.
Virtually no one in the 'soda business' is really geared towards low volume / home usage. Understandable...business is business, so if you want to have drinks for pennies on the dollar a little research and creativity is needed.
Here is what I did: I obtained an ice-bank refrigeration system from a dismantled Cornelius soda machine (via eBay about $300), a McCann Big-Mac carbonator unit (via eBay about $150), two complete and new 10-button WunderBar Gun Systems including manifold (via eBay about $75/ea), eight Sureflo syrup pumps (via eBay about $35/ea), one high pressure (CO2) regulator (via eBay about $40), one low-pressure gas regulator (via eBay about $40), 100' of 3/8" reinforced poly sanitary tubing, 100' of 1/4" reinforced poly sanitary poly tubing (about $50 total for 200'), 100 Otiker Clips/Clamps (via eBay about $50), Brixx calibration cup kit (via eBay about $25), and to finish it all off I got eight coke-style and eight standard-style Bag-N-Box (BIB) syrup connectors (via eBay about $50 total). That stuff combined with a few select plumbing pieces from Home Depot and a filled CO2 tank from my local welding-gas supply house ($100 to start and get 20 pound bottle, $21 to refill and lasts >6 months) and I was off!
It's really straight forward how exactly this equipment plumbs together. The CO2 is the power to move syrup via the Sureflo pumps and carbonate water via the McCann device. Water pressure drives itself through the plumbing and out the gun, either directly or through the McCann Carbonator first. The McCann carbonator needs 100psi CO2 input, the SureFlo pumps 65psi (note the two gas regulators in the list above). The syrup is literally sucked from the boxes via the SureFlo pumps and combined in the Wunderbar manifold to a single stainless steel multi-hose, making the whole operation seem very simple and neat. In fact, the only visable thing in my entire system is the gun and its holster. I stashed the ice-bank system, eight SureFlo pumps and the McCann carbonator in a cabinet above the oven. Next to that, over the refrigerator, another cabinet holds 8 BIB 5 Gallon Syrup boxes. The 8 syrup suction lines are the only thing connecting the two cabinets. So, from the cabinet with the equipment there are eight pressurized syrup output, water and carbonated water lines. These lines run out under the syrup cabinet over the fridge, emerging about 6 feet away under a cabinet that is adjacent to the refrigerator and over the kitchen countertop. I made a custom mount to hold the gun holster just under the cabinet where the glasses are and put a small stainless drain unit on the countertop with a line sloping to intercept the sink's drain pipe.
I'll put up some pictures soon...I think you'll agree, it turned out GREAT. Totally stealthy, easily serviced, and supremely usable! It's really great having in excess of 400 gallons of my eight favorite drinks on-tap. Note that I've configured my gun to dispense 5 carbonated (Coke, Diet, 7-Up, Orange, Giner Ale) drinks and 3 non-carbonated drinks (Lemon Aid, Raspberry Iced Tea, Fruit Punch).
What I learned (aka found out the hard way). NEVER EVER EVER use hose clamps....unless you actually enjoy leaks...leaks of gas, syrup and water. There is a _really_ good reason all professionals use Otiker clamps, namely, you clamp something and it stays exactly that way, CLAMPED. They are expensive, require a dedicated tool to clamp/release, and are 500% worth it. It's a real drag when/if anything leaks (especially invisable gas!) and Otiker clamps don't. Really, they just don't let go or leak. Literally every hose clamp I used eventually caused me grief. I am 100% Otiker clamps now and wish I had not tried to "cheap out" thinking "why not, hose clamps work...". Yeah, they do...for a while. The only other thing I ended up changing about my installation was to insulate all lines and spaces where syrup and/or water exist, either with a few layers of aluminum-bubble foil type insulation (lining the cabinets) or traditional slit-hose type insulation. This is a temperature controlled system, and any heat injection (water/syrup/in lines/in boxes) simply unbalances it resulting in less than perfect drink dispensing. Not to mention it looks cool having chrome-lined cabinets with useful machinery in them hidden in my kitchen.
A word on syrup. It's *VERY* easy to get. I was worried about this originally, but that turned out to be a wasted thought. Virtually any distributor would be happy to have you stop by (call first) and buy some boxes of syrup from them. Just like all the little mom & pop restaurants do - except they expect delivery! I talked my local 7-11 owner into ordering my 7-Up syrup, even though they don't dispense it, it was no problem for him to get. Expect to pay around $50 for 5 gallons of syrup. Drinks all mix with a 5.5:1 ratio, so even with some sloppy calibration and startup you'll get in excess of 30 gallons of tasty drinks per box.
So, see...at about $1.66 per gallon...it's actually cheaper than gasoline now.