The first
coil I used was standard 1/4" copper soft tubing, which worked OK but
had two problems. The first was 50' of 1/4" tubing presents a
lot of resistance to gas flow, so the pressure in the boiler was higher
than I liked, and the second was the water was imparted with a nasty
taste. It seems that very hot water does a good job
dissolving copper. The taste was so strong that I was
concerned about using it in the humidifiers.
The best choice would have been glass, but I didn't want to tackle forming a coil out of glass tubing and I quickly rejected it. Looking on line I found some suppliers for stainless tubing, but it was very expensive and only short lengths were available. People wanted $50 for 10'!
The answer came when I stumbled upon beer cooling equipment. Turns out that stainless steel coils immersed in ice water are used to cool keg beer, and these coils can be purchased pre-formed ready for use. I got mine here. It is a Mico Matic C050L cooling coil. A cheaper coil is here, which I recommend because it is 3/8" tubing vs 5/16" (I found it after I ordered the other one, of course). It is an H680 Stainless draft coil from Beer, Beer and More Beer. Both are 50' coils, which is what you need to cool the steam.
The wood support was made by counting how many loops were in the coil and drilling that many 1/2" holes into the edge of a 2x4. The 2x4 was then riipped into 3 strips. Two of them had the end trimmed so that the holes would be staggered equally as the coil looped around. The strips were then mounted to a board. Be careful to mount the strips at the correct distance from each other, because the coil is rather stiff and does not want to change its coil diameter. Even so, it is a fair amont of work loading the coil onto the mount. By placing the coil on the top and threading the end into the first hole, spool the coil into the mounting holes.
I did this a couple of years ago, and I recall it being difficult. It took at least a half hour. Prepare to be patient.
The boiler end is fitted with a copper compression fitting, the kind used under your sink. The boiler's exhaust fitting was machined to accept it. I keep a flair-nut wrench handy to remove the fitting when I need to empty and reload the boiler.
The cooling fan is a standard $11 three-speed box fan available most places in the summer. Cardboard, wood, and metal scraps were used to direct the air through the coil. The fan only needs to be set to the 'medium' setting to almost completely cool the water to room temperature.
I use a heavy duty 24 hour timer to turn off the still when it is empty. Make sure it can handle the current. This one is 15 amps, most are 10 which is not enough. By trial and error I found that 7 hours will boil the water to within about 1/2" from the top of the heating element. Be sure to never let the element become exposed to the air while hot to prevent a burn-out.
The best choice would have been glass, but I didn't want to tackle forming a coil out of glass tubing and I quickly rejected it. Looking on line I found some suppliers for stainless tubing, but it was very expensive and only short lengths were available. People wanted $50 for 10'!
The answer came when I stumbled upon beer cooling equipment. Turns out that stainless steel coils immersed in ice water are used to cool keg beer, and these coils can be purchased pre-formed ready for use. I got mine here. It is a Mico Matic C050L cooling coil. A cheaper coil is here, which I recommend because it is 3/8" tubing vs 5/16" (I found it after I ordered the other one, of course). It is an H680 Stainless draft coil from Beer, Beer and More Beer. Both are 50' coils, which is what you need to cool the steam.
The wood support was made by counting how many loops were in the coil and drilling that many 1/2" holes into the edge of a 2x4. The 2x4 was then riipped into 3 strips. Two of them had the end trimmed so that the holes would be staggered equally as the coil looped around. The strips were then mounted to a board. Be careful to mount the strips at the correct distance from each other, because the coil is rather stiff and does not want to change its coil diameter. Even so, it is a fair amont of work loading the coil onto the mount. By placing the coil on the top and threading the end into the first hole, spool the coil into the mounting holes.
I did this a couple of years ago, and I recall it being difficult. It took at least a half hour. Prepare to be patient.
The boiler end is fitted with a copper compression fitting, the kind used under your sink. The boiler's exhaust fitting was machined to accept it. I keep a flair-nut wrench handy to remove the fitting when I need to empty and reload the boiler.
The cooling fan is a standard $11 three-speed box fan available most places in the summer. Cardboard, wood, and metal scraps were used to direct the air through the coil. The fan only needs to be set to the 'medium' setting to almost completely cool the water to room temperature.
I use a heavy duty 24 hour timer to turn off the still when it is empty. Make sure it can handle the current. This one is 15 amps, most are 10 which is not enough. By trial and error I found that 7 hours will boil the water to within about 1/2" from the top of the heating element. Be sure to never let the element become exposed to the air while hot to prevent a burn-out.