Still Construction - by a novice

[Trebuchet]

Welcome,

I am currently about to construct an alcohol still from scratch. I will be posting my research, progress as well as my construction results, questions and success stories here within this forum.

I will use Standard English measurements vs. metric – I am American so cut me some slack.

When possible I will list the URLs (web research) for those who have a desire for home distillation.

REMEMBER, this is my very first still and distillation project. Therefore, I will do the work, research and post my mistakes here so you will not have the same turmoil as I.

My Background:
I have simply a “school of life” experience in construction (college summers). I also hold a minor in Chemistry and a “school of Father” Master's Degree.

My “school of Father” degree is that of a wonderful scientist – my father – who was a renowned Environmental Scientist – NEHA, Man of the Year and GEHA Man of the Year for two consecutive years. Therefore, I have over 35yrs of life, onsite experience and practical science from my dearly departed Father.

Essentially, I am an average Joe.

Construction safety
~ Metals
- DO NOT USE ANY GALVANIZED METALS
o Including Soder with Zinc, so check your products!
- Years ago there was a prime example of US College students who mixed up some “hunch punch” – a mixture of Ever Clear (120proof alcohol), Fruit and Fruit Juice – in an assortment of Galvanized Steel Tubs. Subsequently, they accidentally caused several cases of Galvanic (Zinc) Poisoning for those who attended the party.
- Also there are several documented cases of Galvanic Poisoning that lead to death – with animals. (*Why do you think your own pets water and food bowels are made from Stainless Steel?)

~ Heat
- Remember, what you are building will conduct steam. Therefore, you will be building the steam stack and/or a steam handling process. You are essentially your own “pipe fitter” so be careful.
- Allow for steam ‘venting’ or some sort of pressure release component to your design or process.

~ Explosion Safety
- Alcohol – in steam form – is extremely flammable and explosive in the right environment. Act with all due caution!
- VENTILATE, all areas where you are maturing the mash (fermenting) and “cooking” the mash.
- REMEMBER, steam is under high pressure and temperature. DO NOT try to contain it, ONLY control it – allow it to escape and “be free”.

~ Electrolysis - Properties of dissimilar metals
- Essentially, whenever you “mix” different metals and liquids (Copper, Aluminum, and Stainless Steel) you can expect problems with adverse electrolysis. (Electrolysis, Chemical change, especially decomposition, produced in an electrolyte current.)
- Therefore, if a decomposition state exists, this “state” is therefore departed into state of the “less solid” - the liquid mass (your ‘hooch).
- Layman’s terms: your alcohol might assume a somewhat metallic or “off” taste.
- History: Once there was a major Scotch distiller who decided to opt for a Stainless Steel (SS) Pot-type still vs. the traditional Copper Pot-type still. The SS still was exactly like the other Copper stills in every dimension. Their process of making Scotch did not change whatsoever, except the addition of the SS still. Once the final product was distilled the result was catastrophic. The final taste of the Scotch was compared to that of Red Devil Lye. Their “scientists” couldn’t explain why the taste was so “off”. Simply, this is a clear example of electrolysis. Note: They fixed the problem by lining the SS Scotch still with copper.
- Double check all your simple chemical and metal tables, or simply stick with what has worked best throughout the centuries and don’t mix-n-match your metals.
- Either use copper or stainless.
o NOTE: I am going to recommend that you also do NOT use any Aluminum in your distillation process. I have seen some writings (Note: there is a difference between writing and research.) around the alcohol-electrolytic processing with Aluminum and how it could result in a dangerous end solution (i.e., poisoning your hooch).
o I do not think there is any validity to this assumption. But I have noticed two things;
 Aluminum will break down quicker (electrolytic oxidization) under the distillation process than SS or Copper
 Aluminum is NOT used by any of the professional still manufacturers
o Copper or SS is proven safe, use it.

~ Thermodynamics & Fluid Dynamics
- Basic properties of fluid and thermal dynamics in stills;
o Hot “goes to” Cold
o High pressure “goes to” Low pressure
o Steam is a fluid or gas that has undergone a heat and pressure change
o Metal transfers heat to adjoining and connected metals
o Expansion and contraction of metals should be calculated
o *Note: This area will be discussed during the still construction.

~ Learn from the Professionals
- Simply, there are professionals out here (the Web) that have done this for years so ask them specific questions and learn from their designs.
- I am NOT a still making professional.

~ Food Safety
- Essentially, if the product, vessel or device is not made to handle, store, mix or transport “Potable” water, food or food related items, do NOT use it or incorporate it into your distillation process.
- Research on your own your;
o Plastics
o Fittings
o Sealants (Food safe silicon, etc.)
o Proper metals (NO galvanized (Zinc) metals)
o Containers

URL Listing I used during my initial research

Step by Step Still Construction Process
moonshinestill.com/page2.htm

*The BEST distillation web site
http://homedistiller.org/" onclick="window.open(this.href);return false;" rel="nofollow

Manual for making Alcohol Fuel (VERY GOOD)
http://journeytoforever.org/biofuel_lib ... l_ToC.html" onclick="window.open(this.href);return false;" rel="nofollow

A copy right Adobe document (VERY comprehensive)
http://www.distillationgroup.com/distil ... 2/H002.pdf" onclick="window.open(this.href);return false;" rel="nofollow

Pot Still – Malt Whiskey
http://www.sgoc.de/making.html" onclick="window.open(this.href);return false;" rel="nofollow

Making Bourbon Whiskey
http://www.cocktailtimes.com/distillery ... ndex.shtml" onclick="window.open(this.href);return false;" rel="nofollow

Making Scotch Whiskey
http://running_on_alcohol.tripod.com/id34.html" onclick="window.open(this.href);return false;" rel="nofollow

Let’s see how things proceed shall we?

[Professor Duck]

Hi! Welcome to the forums, it's always good to see newcomers who have done some research and can contribute to the pool of knowledge.

[KatoFong]

Has anyone seen or experienced what Trebuchet is talking about regarding adverse electrolysis? I'm about to construct a potstill and want to use a stainless steel pot with copper piping. I've used glass and copper with no problems before, but that, of course, is a completely different can of beans.

Should I try to find copper cookware instead. I gather that can get fairly expensive.

[Grayson_Stewart]

This is called galvanic corrosion, electolysis is a wrongfully used term. Copper is a metal that is difficult to polarize and as such would cause steel to deteriorate at a faster rate. With that said size does in fact matter. A steel washer holding a copper plate will corrode the steel washer quickly, while a copper washer holding a steel plate will not corrode the steel quickly. I would assume the smaller contact area of a copper column to a stainless keg would also hold true because I have not seen any sign of corrosion in my setup.

Stainless steels can corrode but generally this entire discussion is about differing metals burried in the ground or emmersed in salt water. There has to be a medium for the transfer of electrons.

Stainless and copper are very close is the galvanic series (ie. have similiar electrical potential) and therefore not as subject to corrosion due to dissimiliar metals. Also they are both on the least reactive end (cathodes) and not as readilly corroded.
As long as you don't take your stainless keg with copper column attached and soak it in a sea water solution between runs you should be fine.

[KatoFong]

Good. Because I was having a hell of a time finding a copper pot.

[Guest]

another major difficulty with differing metals such as this happens when you have a current running through them, I'm assuming your still won't.

[Grayson_Stewart]

electrical current... aka a medium for elctrons to pass through.

[Gypsy Davey]

Hi,

I've built two (and a half counting repairs) stills and I can offer these bits of wisdom and a quick description:

1. Pot stills are not under a lot ofpressure if you make your column large enough. There should be an unobstructed path down the pipes from the boiling mash in the pot to daylight. You only need to worry if your condenser shuts down.

2. I use plumber's silver solder. 95% tin 5% silver and copper. Works fine. I'm not worried.

3. Aquarium silicon caulk is your best friend
3a. Your second best is flour and water paste.

4. To test my stills, I filled the pot with water and got a cork to stop up the condenser output tube. As the water boiled I looked for steam leaks. This method also lets you see how good your flour/water caulk is. Once the leaks are fixed, I ran water through and then I scrub the whole thing with vinegar before each finishing run.

5. I clean all the copper parts completely before assembly. That means a vinegar soak, hard scrub and good rinse 'til they shine.

Construction:

My first still is a monster, a 25" column of 2" copper pipe, turning 90 deg. to a thermometer fitting, and 45 deg. and a step down to 1.5" pipe into the 4' water jacket condenser. Inside the condenser the pipe steps down to 1/2" for the output. Damn thing ran almost $200 in copper.

The thermometer fitting is a 2"x3/4"x2" "Tee" fitting. A drilled cork fits in the 3/4" hole with the thermometer in the cork. This gives me a temp. reading right before the condenser.

This sits on a modified Korean dumpling steamer. I found this pot with a clamp-down lid and silicone gasket. In the center was a 7" glass window. I removed the window and had a SS bowl welded to the top. On the bottom (now top) of the bowl I drilled a hole and soldered a 2" copper pipe union. The still "head" slides down into this easily.

To run, I seal the joint between the pot and column with flour and water and put the thing on the stove. Turn on the fan and turn on the heat and I'm off.

Of course I had to build a large wood stand to support it and it fill up my whole kitchen.

double run, all malt "whisky" aged in 1/2 full quart jars with 3-6 oak chips for 30 days-yummy.

Problems: The steamer is only 3.5 gal, so every batch of wash needs 2 runs. Plus this thing is too big.

So...

I bought a SS brewing kettle (6.5 gal/30 L) for my pot. Put a cork ring around the lid, covered the silicone. I bolted and siliconed a SS bowl onto the lid and cut out a large circle in the lid with a dremel tool. The top of this gets the same 2" hole (hole saw and dremel). This time I cut a 2" hole in a 4" copper square and soldered this to the 2" union as a flange. Lots of silicone inside and out and it is attached to the top of the lid. I hold the lid in place with 6 spring clamps (4" size) I need 3 to get a good seal, and I think 6 makes for a good safety factor.

The new head is a 20" column, right angle joint to a 18" Lyne arm, THermometer fitting at the end with a 45 deg. bend and a single fitting to step down to 1/2". The water jacket condenser is right there, this time it is 1" pipe around the 1/2" pipe and only 18" long.

The whole thing sits on the counter next to the stove.

Cooling water comes from the sink (municipal supply)

No finished product yet. The mid-stage tastes OK.

[Guest]

hey Gypsy,

I'm not so sure that advising someone to completely seal a still and boil water in it like that is a good idea. It would definately show leaks, but could build up pressure that could crack the seams or worse.

[Grayson_Stewart]

Exactly....All that will be accomplished is blowing the cork out or making a leak somewhere because you have built up pressure in the system...and heaven forbid if the cork has been driven into the pipe....BOOM!

A much safer way is to simply assemble the boiler and all piping and then fill to the very top with water. If there is a leak it will be found.....and its alot easier to search for leaks by running your hands over a pipe filled with cool water than one with 212 degree F steam.

[linw]

Sounds like a MUCH more sensible idea to me, Grayson!

[goschmil]

I have built an all stainless 42" tower still (my first), the only thing on it that is not 316 Pharma grade stainless is the heating element which is a standard 1500W 120V electric water heater element. Everything operated correctly( as I'd expected since I got my technical info. from this site) BUT the distillate from a standard 18% sugar based wash smelled and tasted something "funky" like old gym socks almost. I was able to clean it up by repeated carbon filtration( 3 or 4 times). It was not until I came across a paragraph on tis site regarding the necessity of having some copper in the path of the distillate/wash, something about the chemical reaction in the stainless with the absence of copper oxide. Well, you guys were right again; I stacked 6 copper scrubbers above the glass beads in my tower and Goodbye "funk", have not had that problem since.

[Guest]

Friend; If you got your technical information from this site, can you direct me to the reference to use glass beads.

My suggestion would be, get rid of ALL the glass beads and replace them with STRUCTURED COPPER MESH.

[goschmil]

The HETP for a packing depends on its:

Size (smaller objects pack together better). The size also needs to be in proportion to the column diameter too
Voidage (need to allow room for the gas & liquid to flow around them, don’t want to block the column off)
Surface area (eg how many square meters of surface you have per cubic meter of packing – the more surface area, the more places for the liquid & vapour to mingle)
The amount of liquid & vapour flowing around it
Typical HETPs for common packings are :

Packing HETP
Stainless Steel Wool Scrubbers 0.13 m
Marbles (10mm diameter) 0.33 m
6mm Ceramic Raschig Rings 0.24 m
13mm Ceramic Raschig Rings 0.38 m

Zoran suggests that in some cases marbles may be as effective as a 0.2m HETP.


This is a section I found under Reflux Still design under the Theory header

[The Chemist]

HETP=height equivalent to one theoretical plate

A horrible mingling of old tech and science-speak. Still, quite useful.