Still Design Concepts

The following are some of the factors needing to be considered if building a still.

Heating

Preferably electric - easy to regulate the power, and no flame source to ignite stray vapours. Keeping the element within the vessel further reduces the risk, however it needs to be positioned such that you can easily clean around it. Internal also means that you always have to keep a minimum amount of liquid in the still, so that it wont boil dry. On mine this is about 6L - quite a bit if just wanting to do a small experimental run. Some stills are mounted with two elements - the second is used to speed up the pre-heating period.

If you are going to use gas, heed the following advice of David Reid's :
    Gas for heating is perfectly safe as long as it doesn't come into contact with alcohol, ie: the naked flame must not come into contact with alcohol either in the liquid or vapour form. At a very low % nothing will happen, in the middle range the alcohol will burn, and at a high % it will detonate and explode. I use gas (9kg l.p.g. bottle) with my small glass still that I use for experimenting, and for botanicals. The requirements you must have or meet are as follows:
    1) You must have no leaks.
    2) You must have accurate temperature control, or enough experience to know what is happening at all times and pretty well what the temperature is.
    3) You should remain in attendance at all times and not leave the still unattended even for a short time.
    4) The area it is used in should be well ventilated so there is no risk of alcohol fumes building up and causing an explosion.
    5) Ideally the spirit receiver should be at least 10 to 12' away from the gas flame so there is no risks of spillage and consequent fire or explosion.
    6) Hoses conveying the alcohol from the condenser to the receiver should not be able to be burnt, melted, or able to come into contact with the hot still body or boiler.
    Gas is a good medium but you must know what you are doing. Like anything to do with fire "A good servant but a bad master". For your first still I would not recommend it. If you read enough history books you will see that a lot of early moonshiners did themselves quite a bit of harm as well as burn down quite a number of buildings. Today with good regulators and controls there is no reason why you should come to harm so if that is what you want to use go ahead but be sure you know what you are doing before you do. Having said that I would point out that there have been and there are from time to time quite a number of fried corpses from people who think they know what they are doing with electricity but don't. Good luck with whatever path you choose and don't be afraid to ask questions. Have a good talk to your local gas company, B.O.C GAS Co, Air Liquide or whoever your local l.p.g. supplier is.

Some people also use a water bath or the like, to avoid direct contact with the heat, which can cause scorching of the grains or fruit if not carefully done. Heres a great summary of different methods tried by Todd ...
    I just did a s**t load of research and garage lab experiments with water baths. Here are my findings.

    Your wash boiler MUST be metallic. Glass does not conduct heat well enough to boil ETOH in a water bath. I am "researching" small scale absinthe and gin distillations. I use quart and gallon unlined, new paint cans. Works fairly well with only water. Doesn't quite dig down deep enough to collect any appreciable tails, but my loss is still only 7%

    I would recommend against glycols, particularly in your kitchen. Yes these will raise the BP a few degrees when mixed with water (never heat pure glycol), but so will salts. Glycols give off copious amounts of vapour when heated. Ever wonder why propylene glycols are used in fogging machines. When pure glycols are heated, the vapours are combustible. One splash on the burning element and you'll need a fire extinguisher real fast (don't ask me how I know this ). If you must try glycols, use propylene glycol, not ethylene glycol. The former is non-toxic, the later is. You can get "environmentally friendly" antifreeze at any Autozone.

    Mineral oil and cooking oils have been mentioned on sci.chem as a bath heating medium. Vegetable oils tend to break down quickly so aren't much good for re-use. Solid animal and vegetable fats (lard, Crisco) do better for re-use.

    Once I solved the glass versus metal thing, I stopped looking for additives to raise BP of water and settled for process crawling to a standstill at a vapor temp of around 198-199F.

Temperature Control

I haven't got this fancy, rather just run with it at one setting, and ensure that you have enough cooling water. The amount of alcohol in the wash determines what temperature it will boil at, not the amount of power supplied. The extra power will increase the amount of vapour you produce, though, and can cause problems if the column diameter is too small. Match the power input to the column size. Some stills have two heating elements - give the extra boost while heating up to temperature, then just switch back to one, to keep it simmering while doing the distilling.

Diameter

The more surface area, the easier for the vapour to come off. So go for wide rather than tall for the boiling pot.

Boiling Kettle / Pot

These can be made from a number of readily available items .. old hot water cylinders, pressure cookers, tea urns, soup pans & large bowls joined mouth-to-mouth, etc. Just make sure that they will stand stable, are easy to empty without giving yourself a hernia, and are easy to clean.

Alex's is fairly simple :
    I built my boiler out of cheap $8 stainless steel stock pot and cheap $6 stainless steel salad bowl. I clamp them together with small stationary black steel spring paper clips. It works fine. You would need to make sure that both rims fit and both rims have enough surface and the lip for the paper clips to grab on
CX goes into more details ...
    The challenge: To find a reasonably sturdy high quality container of either stainless steel or copper to be adapted for use as a boiler.

    Possible solutions:

    1. Milk can. So far, my research has led me to believe that this is probably the most economical, simple, and "cleanest" solution for a home still builder. The e-book "Building a World Class Home Distillation Apparatus" mentions this option. The thing that I personally find most compelling about the milk can option is that the lids fit quite well, and should allow for a good seal. So, where does one find reasonably priced milk cans? One source is swap meets or eBay. Look for "Firestone" stainless steel milk cans. They have a pleasant curved shape and should make an attractive boiler. There are currently a couple for auction on eBay. From time to time, copper milk cans come up for auction as well. As they are all vintage, I would be suspicious of lead soldering in them. For this reason I have personally chosen to ignore the copper milk cans. (Despite the temptation to use one being quite high!) The used milk cans tend to go for quite a bit, often over $100 U.S. Why not get a new one? I was able to find some reasonably priced SS milk cans. (made in India) They are available in 20L (5 Gal US) and 40L (10 Gal US) and sell for $124 and $139 US. http://non-electric.lehmans.com/search#w=milk%20can&asug= Since I'm impatient, and I hate swap meets, I am very seriously considering this route.

    2. Converted SS Beer Keg. Kegs are a commodity item still in active use, and hence less rare than milk cans. For the volume they hold, they are surely the most economical SS vessel you can buy. If you have tools and the know-how, converting a keg is probably the way to go. You can get old kegs at salvage yards or brewing companies. Keep in mind that any keg you find in a salvage yard is there for a reason. They may have small punctures or cracks, so do a through inspection. If you want deluxe inspected and professionally converted kegs you can get them from Sabco. Sabco sells a couple of models that are pretty much pre adapted for our collective hobby. (Though they are not marketed that way!) One is called the "Selective Sankey" which has a 4" port and pressure valve installed on the top. Perfect! The only problem is the price at a wallet thinning $196.75 US. :-( The other model of particular interest is the DIY brewers kit, which is simply a keg with a perfect 12" hole cut in the top. At more spouse appeasing $59.95 US, it may be the way to go for the moon-shiner on a budget. They will customize kegs also, so if you want, for example, a half keg instead of a full keg, or you want a ball valve attached to the base of the keg, they will do that. (Extras cost about $50 US per item) Sabco sells a 12" pot lid which purportedly fits the hole perfectly, but I would consider using a salad bowl as illustrated in "Building a World Class Home Distillation Apparatus" Sabcos web site is http:www.kegs.com I like the keg option, but I don't want to spend $200 for the "Selective Sankey" (or $250 if I have them put a 2" NPT on the top rather then a "Sankey Valve" ) , and the DIY kit, while cheaper then a milk can, is not as "clean". I worry about getting a good seal on the lid.

    3. Stockpot and/or Salad Bowl / dual Salad Bowl. This is another attractive option, especially for smaller boilers. Negatives regarding this choice are that large stockpots can be very expensive, and you must track down a salad bowl that fits the top of the stockpot perfectly. If the lid of the stockpot fits well enough, it can be used, but if it is not thick enough it will not provide proper support for the column. Some interesting copper stockpots pop up from time to time on eBay. The Stock pot option is an interesting one, but can also be frustrating as 5-10 gallon SS stockpots are rarely reasonably priced. I personally have had major frustration attempting to exercise this option, so I've pretty much abandoned it.

    4. Copper water heater tanks. After a few calls to some local scrap yards, I have learned that copper water heater tanks are quite rare these days. In my humble opinion, they are the "brass ring" for anyone interested in building a traditional all copper still. If you have one of these, or find one, I envy you. I'm keeping my ear to the ground regarding any that might pop up, but I also have to keep my project moving along, so for they time being I need to file the possibility of a copper tank under "Pipe Dream" to maintain my sanity.

    5. Windfall items. If you have a keg, or a tank, or a stockpot etc, of the proper size that you got for free, use it! You are never going to find anything for sale that is as good unless you get really lucky.

Lid

Needs to be sealed well, but not to cause risk of pressure build up if the condenser blocks. Some simply push on, and are held there by their own weight. Others are fastened down with a couple of clips. You may want to consider some form of pressure relief valve - eg a rubber grommet pushed into place. Some lids use a length of soft PVC tubing split along its length to fit around the edge of the lid - this deforms when the lid is fastened, and helps maintain a good seal. If doing a wash that is prone to vigorous boiling (eg malt based, or still have unfermented sugars present), I'll use a couple of "bungy cords" - rubber cords with a hook each end - to help hold the "pushed on" lid in place. Remember to open the lid, or a valve in it, immediately after finishing, or else the cooling vapour will cause a vacuum, which can collapse your still if air can't get back into the system.

I reckon the only time the shape of the lid would be important is if you're making a traditional pot still, where you're relying on the shape of the lid to provide extra surface area for cooling so as to induce a small amount of internal reflux, and then want to distribute this internal reflux evenly so as to get it working effectively.

But in a reflux still, where you're generating a far greater amount of reflux, and from the top of the column, you're counting on it working its magic over the column packing (to do the equivalent of say 8-10 redistillations), and not via the lid (where you might get less than half an effective redistillation if it had heaps of surface area ?)

In terms of whether or not putting the column connection off-center is going to affect the vapour flow up the column etc, basic hydraulics tells us that the pressure in a container is equal in all directions - e.g. a car tire will go flat whether the hole is at the top or at the bottom - so in our case, the steam will head out the hole in the lid, no matter where we put it.

Condenser

You don't want this to block, so have it so that it can be regularly cleaned; if using a long length of tubing (say through a cooling tank), make sure you don't accidentally crimp it.

Cooling Water

You need plenty of this. Locate your still close to a tap & drain. Adjust the flow of cooling water so that the distillate is warm to touch, but not hot nor cold. If running off a tank or small well, and can't afford the excessive consumption, try a closed system. Use a small pump to circulate the water out of a large rubbish bin, through the condenser, and then draining over a wide, sloping board back into the bin (eg air cooling as it does so). I had trouble keeping the water cool enough when the air temperature was in the 30's (C), but it should be fine in cooler climates. Another solution is to freeze 2L PET softdrink bottles of water in your freezer, and put these into the water bin should it all get too hot. Passing the inlet tubing through a bag of crushed ice also works to cool it.

Cornfed writes ...
    I built a system to recirculate my condenser coolant (see the photos in the files section of the Distillers group at http://www.yahoogroups.com ). I have a Nixon-Stone basic design still. It has a 36 inch reflux column packed with copper scrubbers. It is well insulated with fiberglass matting and then wrapped with a heavy canvas material. I made the still out of 2 inch copper and then used 1/4 inch OD tubing for my 24 inch long condensor coil. I just upsized everything to fit the design. I couldnt see running all of that fresh water down the drain. So I built a reclaiming and recirculation system for it.

    I run coolant from a 5 gallon bucket thru a pump to the condensor unit, and then thru a radiator assembly and back to the bucket. There is a bypass valve assembly built in so I can regulate flow thru the condenser. During summer months, I operate a fan over the radiator.

    The main components are the radiator and the circulation pump. I discovered a used condensor unit from a huge refrigeration unit at a scrap yard. It was constructed out of 20 feet of copper tubing with aluminum cooling fins.($5 US) After a few expensive misadventures, I located a pump in the correct size and function. This is a pump designed to fill and drain a waterbed and has attachments so you could drain a basement floor or a fishtank or some small pumping job like that. This one was made by Simer Pump company. http://www.simerpump.com/ (about $85 US) The one I used is under the utility pump section and then clear down at the bottom. It is rated at 6 GPM and has the capability of a 35 foot static head. I have found that after the coolant has gone thru the cycle I am getting one gal a minute out of it. I discoverd by chance a series of copper fittings that connect from 1/4 OD tubing to hose bib. SO I connected all of it together with these so I can disassemble quickly and easily if necessary. I bought my pump at a regional sized hardware/lumber/build-it store called Menards. I am sure a Lowes or another name would have then too.

    This is set up in my garage. I live in the area of the world where we have a winter. So I wanted to be able to use this year round without dealing with frozen lines. The Pink substance in the lines and the bucket is propylene glycol. Otherwise known as Recreational Vehicle /Marine Antifreeze. I needed a substance that would not freeze, and would not cause more of my hair to fall out if I developed a internal leak. This stuff is non toxic to humans and pets. It doesnt taste good, just wont kill ya. It lists a "GRAS" rating from the food and drug administration on the lable. (Generally Regarded As Safe) In the summer I flush lines and return to water. I save all of the buckets, so I just put the return line in then and run the pump until the bucket is empty. 7 gallons later I am done. Then I dunp a gallon of fresh water in and run it thru to finish flush and I am done. 8 minutes for the conversion.
Russ writes ...
    I have used a 'modified' water cooler base for my cooling...my copper piping coils into the 'bucket' that would normally sit under the cooler bottle - it is large enough to take a coil of over 5 metres of pipe. A few modifications (dead easy) to the thermostat has allowed me to cool it very quickly from seriously cold to either slushy or even ice. I have even fitted a pump which forces some of the chilled water through a jacket around the upright pipe. It has proven to be very efficient and best of all the coolers can be obtained secondhand really cheaply. If anybody is interested they should have a look at http://www.DrinksProblems.com - (brothers company) - they specialise in Espresso machine servicing, boiler testing, pumps etc and have been a very useful source for spare parts. they are happy to ship stuff as well.

Water Control

If you want to get real fancy, you can try to adjust the cooling so that it increases the reflux ratio at later stages of the run, in order to maintain high purity output. I don't bother - just check it every half hour or so by finger to see if it is too hot & the flowrate needs upping.

Packed Reflux Column

As a general rule of thumb this should be 30-55mm diameter, and 600-1000 mm tall (14-20 times the diameter). (see Reflux Still Design Calculations to accurately work this out for your requirements). If too narrow, the liquid trying to drain back into the still will be blown out the condensor by the vapour; if too wide it will cool too much (no vapour get out - all condenses prematurely), or there will be inadaquate contact between the liquid & vapour and not much purifying will happen. If in doubt, go slightly too large, then shove a stainless steel rod or two up through the packing to take up some of the space. Packing best to use is stainless steel wool / turnings. Pack as much in as possible, but loose enough that you can still easily breath through the tube if you try. Position the pre-condensor ABOVE the packing, so that the liquid it condenses falls back through the packing. Some designs (eg Partyman's & StillMakers) have the condensor below the packing. Although these columns will still work, the only purification taking place is via vapour/liquid that has cooled inside the packing - quite a lesser amount. The greater the reflux ratio through the packing (the ratio of falling liquid to rising vapour), the cleaner & stronger your alcohol will be.

Breaking up the Column

Often these columns are quite tall (1.5m), so its nice to be able to break them down into a couple of sections to make them easier to store, or to be able to shorten the column say for when doing flavoured runs or stripping the wash.

Cornfed writes...
    Try going to a automotive parts supply house and find a exhaust tubing expander. It is a specialty hand tool that has a series of tapered sections arranged around two wedge pieces that are threaded for a through bolt. The tool is placed inside of the tubing. As you tighten the bolt, the wedges expand the tapered sections and the tubing to the size that you need. You can go too far and split the sidewall out. You could expand one side of each connection and then you would have a simple slip joint at each section end. You could use the flour water solution to seal each joint or you could use wrap around exhaust clamps that are solid stainless steel sheeting and come in widths from 1 inch to 6 inches. These are used for large diesel engine exhaust connections.
John suggests professional help ...
    The hand tool you are referring to is not really designed for expanding exhaust tubing, rather it is to straighten out collapsed sections of tube that had previously been expanded in a hydraulic tube bender used by muffler shops, While it may just do the job on exhaust tube it certainly won't touch stainless or hardened copper. The grade of mild steel tube used in automotive exhaust systems has lead in it to make it easier to bend and be expanded. The band clamps you refer to are not used with expanded joints, they are used for straight butt joints and are far from water tight.

    The subject of joining various bits of tube together is a fairly common one on this list, and if I may make a few suggestions on this common problem: there is a point when the oft used phrase "don't try this at home kids" really is applicable here. I know that part of the fun in home distilling is to be able to say you "made it yourself", but there are times when professional help is the way to go. I think you would be surprised to find that small welding jobs can be done for remarkably little money and even more likely, a quantity of alcoholic beverages will work as currency. More often than not, a small welding shop will not care what you are making, as you are simply going to ask for some bits of metal to be joined together. When I started on my still project, any time I had a question I would simply say "I'm making a still". Universally, everyone had helpful suggestions and usually added stories of someone they knew that had a still... The big advantage of getting a pro to help is thet they will have better and bigger equipment than you, which will turn a difficult job at home, into a few minuites for a skilled tradesman, and the results will be much more satisfactory as well.

Pot Still Head

Commercial stills sometimes have the head neck in, then flare out again, before heading off towards the lyne arm. This is to encourage a little of the vapour to condense out & return to the still. The more this happens, the cleaner the liquor will be.

Thermometer

You need to be able to track the progress of the distillation. For pot stills the thermometer needs to be mounted in the head, whereas it should be at the top of the packed column in a reflux still. In both cases, its just prior to the final condensor.

Cleaning

Make sure everything can be easily disassembled for easy & regular cleaning. You may wish to have a tap in the base of the boiling pot to help drain out the spent wash at the end of a run (20+ L of boiling liquid is fun to manhandle !).

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