evil_lurker
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Copper plating stainless steel...
I'd like to copper plate the inside of my 304ss moonshine err.. ethanol still with copper to see if it would give some better flavor err... higher
proof to the distillate. 
Did a yahoo search and it didn't turn up much of anything useful... if anyone could give me some pointers on where to look it would be great.
Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in
beer.
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Klute
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Couldn't the coppe rin some way promote dehydrogeantion to acetaldehdye, and further polymerisations/condensations?
I have a relative distilling his own eau-de-vie, an dhe told me he often got problems with green copper compounds passing in the first
fractions, and sometimes contaminating the best fractions (which were obviously re-distilled).
But i guess theses issues can't be that bad as copper still shave been used since eternity, no?
What is supposed to the avanteg of using copper as the still?
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
-Alice Parr
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Twospoons
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Copper is supposed to destroy sulphur compounds resulting from fermentation, which produce 'off' flavours in the distillate. The sulphur source is
usually residual metabisulphite from sterilizing.
Plating is going to be a lot harder than simply using copper column packing, and possibly less effective. Personally I use knitted copper mesh as
the column packing, and I have to say it works extremely well, both as scrubber and packing.
I've even dug out the place I bought it from
http://www.amphora-society.com/equip_1.html
Aren't I nice?
[Edited on 25-6-2008 by Twospoons]
Helicopter: "helico" -> spiral, "pter" -> with wings
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smuv
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I played around with copper plating stainless for simular purposes.
I cleaned the SS piece with IPA and water, then cleaned it electrolytically in a dilute sulfuric acid bath. After cleaning the piece was removed and
2 copper electrodes put in; current was passed through for about a half hour until Cu concentration seemed to come to a steady state (judged by
color). Then one of the copper electrodes was removed and the SS piece was connected as the cathode and 5v was passed through (cant think of the
current density but it was pretty high). A strike was plated, and then removed by reversing the polarity (to further clean metal surface), then
polarity is reversed again to start plating the piece again. The polarity is reversed from time to time for short periods to keep the surface of the
piece smoother. The piece is plated in this fashion until you are happy with the thickness.
I dont have in depth notes for this because it worked the first time and many times without any real measurements. You could play around with the
sulfuric acid concentration to stop the build up of copper gunk on the SS piece (which probably inhibits the smoothness and current efficiency). In
my experience the luster of the peice is crappy, but the Cu certainly adheres well to the piece.
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zed
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The important step is anodizing the stainless steel to activate it. Once activated, plating isn't hard. I remember performing this routine on
chromium. It worked well.
I simply used a solution of copper sulfate.
This handy technique, makes it easy to solder to stainless steel or chromium. Normally, it is difficult to solder to stainless steel, and soldering
to chromium may prove impossible.
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kclo4
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That sounds tricky to electroplate iron with copper.
The moment the copper sulfate solution hits the iron wouldn't it precipitate the copper on to the iron and turn the iron into sulfate?
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Contrabasso
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The proof limit is the result of the EtOH/water azeotrope you cannot distill past that.
Plating onto stainless is not easy! Nothing really sticks well.
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watson.fawkes
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Caswell sells a stainless steel activator, which I assume is a nickel salt, since it asks for a nickel electrode. After this strike plate, you'd put on whatever
other coating you want.
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smuv
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Very true. You can coat it; and the coating will be fairly scratch resistant, but if you solder to it the joint will be weak. I am sure there is a
way of plating a more adherent strike with copper sulfate; but I havn't figured it out (although I havn't searched much patent literature).
Copper onto iron is dead easy...making it shiny is harder, but for the purposes of protecting from oxidation, you can just put the piece into a copper
sulfate solution and have the piece be the ANODE, turn on the power for a minute to remove the oxide coating and then let the peice sit; it will have
a nice coating of copper in about 30 seconds (I suppose this isnt electroplating really).
"Titanium tetrachloride…You sly temptress." --Walter Bishop
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watson.fawkes
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P.S. I saw some reference on the Caswell forums to "Wood's Process". In one old reference, this was a mixture for plating brass with cyanides of
copper, zinc, and potassium. In a patent reference, it was apparently nickel chloride. There was another Wood's process involving steel-making,
which isn't relevant.
The Caswell solution says you supply your muriatic acid. So I'm guessing their product is just nickel chloride. It works better (again I'm assuming)
because the excess chloride ion complexes the nickel.
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Contrabasso
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Onto steel, my old firm used to plate a nickel flash which was very thin, then a copper from a pyrophosphate. This solution plates a leveling copper
layer - which tends to fill in small scratches naturally. We then put three separate nickels over that then a chrome.
To get a bright finish the chrome had to have brighteners added these were always odd chemicals that survived for a while in the hot chromic acid but
needed regular analysis and top-up.
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Ragnarok
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| Quote: | Originally posted by Klute
I have a relative distilling his own eau-de-vie, an dhe told me he often got problems with green copper compounds passing in the first
fractions, and sometimes contaminating the best fractions (which were obviously re-distilled).
But i guess theses issues can't be that bad as copper still shave been used since eternity, no?
What is supposed to the avanteg of using copper as the still? |
To get rid of the blue coloring, me and my dad used to wash the condenser (made of brass, but it's the same thing) with vinegar (actually a 1:1
mixture of vinegar and water, 'cause we're cheap bastards). You have to do this before each season. Like if you distill 10 batches in a few days, wash
it once on day one, rinse and use. If you take long breaks between batches, you have to wash it before each session.
The best way we found is to plug one end of the condenser, put in a liter of washing mixture, plug the other end and rotate it from time to time,
empty, rinse and distill.
Another good thing is to add a cup of calcium hydroxide solution to the batch before you distill it, to trap any acids before they can get into your
product. The acid problem usually occurs when our plums stay for too long in the barrels we use as fermenters. (details on the technology on YIM, for
those interested)
And to keep on topic, copper is the only material used traditionally in such endeavors, and almost every household in the countryside has a still.
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zed
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If you were to read the "Foxfire" books, you might find some tips on distilling beverage alcohol. I say might, because I'm not sure that I actually
read about it there.
Seems to me they suggested copper, copper, copper. No solder. All joints sealed by wheat paste.
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ElectroWin
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btw, my understanding of the reason why you want copper is, that some mashes have pectins in them, which the yeast metabolize to methanol; and copper
catalyzes the transformation of methanol to formaldehyde, which is easier to separate from the ethanol.
i was able to apply a thin plate of copper to mild steel electrolessly, but my test did not adhere well.
i quote a finishing.com source:
"Plating of stainless steel starts with a Wood's Nickel Strike. The thing is, you can't successfully plate onto tarnish or a passive skin, you must
plate on fresh, active metal -- but stainless steel passivates almost instantly. The nickel strike simultaneously dissolves the tarnish while it
deposits a fresh layer of nickel plating." -- http://www.finishing.com/153/52.shtml
[Edited on 2013-7-23 by ElectroWin]
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