This might seem like a stupid question, but I'll ask anyway.  SWIM built a still for distilling alcohol some time ago from copper tubing and fittings.  Works quite well, apparently.  He's decided it'd be quite simple to build a snazzy little vacuum adapter, and was thinking he could convert it for use in distilling uh... essential oils and stuff.
Anyways, he got to thinking that this might be a problem in that copper could form organometallic contaminants which could cause failed reactions, or dicsolour or even poison any final product.  What is the likelyhood of this?  Could he perhaps coat the inside of the tubing with some sort of polymer coating?  Simple PVC glue comes to mind as something that may be suitably chemical resistant.  Note that the "flasks" are made of glass, so product wouldn't be in contact with copper for overlong, but I don't really know.  Can anyone offer an opinion?

You're right about one thing, it's a stupid question    Copper was the material that essential oil stills were made from in times of yore, that fact could have been answered using various search engines:

http://www.cairns.net.au/~sharefin/Cyclopedia/distillation.html

http://www.countryadvertiser.com/distilling.html

http://www.levity.com/alchemy/jfren_1.html

http://80.1911encyclopedia.org/D/DI/DISTILLATION.htm

http://www.swsbm.com/AJP/AJP_1888_No_7.pdf

Rules about copper: no acids, no bases. Everything else is game! I'm using a copper still right now to purify some old fruit juice gone bad.

If you all (inventor included) may have a look at:

https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000397780-file_rrra.jpg" title="View this image">

There is one thing obvious, so obvious it hurts to say:
Replace the single 3/8 copper tube by a SS (stainless steel 316 preferred) and you have an universal still as this is the only part coming in contact with aggressive chemicals. Or make a SS inlay. Or make a teflon inlay, PVC inlay, PP, HDPE, PE whatever suites your needs for resistance and temperature.

please send the noble price to my home address directly, thanks.

And as a extra for free without any charges:
If you think seals, "VITON" is the word for GOOGLE.
ORG

Nice idea. The trouble is that it is very difficult to work with and more expensive to use stainless steel. It sounds like an obvious idea until you, Joe Blow, try and do it yourself.

The nice thing about what I purposed is that it requires nothing other than a pipe-cutter and some epoxy to build a very-effective low-cost nearly-unbreakable simple distillation rig. Unfortunately it's use is quite limited as you noted. If it was more effective, more people would already be using it.  

If you want better designs on how to make copper and stainless steel stills I suggest you look thru the ideas at

http://www.homedistiller.org/

Actually I admire the practical design you made Chromic and the "obvious" could only get obvious to me by looking at what you buildt. The SS tube replacement was the first I thought of, but much better is the "inlay" as it does in no way complcate the construction is easy cheap to free and requires not much more than a look at some charts for heat and chemical resistance of plastics.

I recognize now that my post was prone for misinterpretation - my guilt, sorry. I intended  to launch a useful addon mainly - not more not less. Comments on this addon would be welcome also ideas how to connect this and similar devices to standard glass in a effective way good enough for use with slight pressure and  vacuum.

no offense intended Chromic!
ORG

Post 202511

(lugh: "Re: Simply Constructed Soxhlet", Novel Discourse)

Post 242483 (missing)

(lugh: "Re: Coke bottle adapter", Chemicals & Equipment)
   

Cooper is often (always) used to distill liquor from mash. The thing about it is, that cooper reacts with some contents of the mash (mainly sulphur molecules). That makes the liquor better.
I wouldn´t use cooper apparatus for (all) organic syntheses, that´s what they aren´t made for.

If someone needed a quick inexpensive stainless steel condenser, the local hardware vendor sells stainless steel gas applance connector tubes. They are flexible and resemble ribbed condoms, just like the inside of many glass condensers. They come in various diameters and lengths.

  Those who have messed with copper condensers may already have encountered this, but swim suggests, before using one, clean and scrub the hell out of it, before use, even if it looks shiny and new. Swim has wound up with discolored solvents more than once as a result of copper tubing that looked nice and shiny clean, but wasn't. 

http://www.moonshine-still.com/still.pdf

If you want a serious still, design a Nixon-Stone adapter instead of the idea featured in the above article. Look thru www.homedistiller.org for ideas. The general idea is an (often insulated) column (often 1-2m), with an outlet valve, then a condenser on top. You control the reflux ratio easily by adjusting the valve and only cool at the top of the column increasing efficiency. You can get azeotropes in no time with a still such as this... of course, I have found these stills to be only useful at recycling solvents, etc.