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Re: Electroplating
On Tue, 25 Aug 1998, Tesla List wrote:
> >supply. So there is little danger of water contamination. As far as
> >being poisoned is concerned the processes that I intend to use will not
> >involve the use of potassium cyanide, or any of the nastier chemicals
>
> That is a very good idea. Some chemicals are so poisonous it is hard
> to imagine. (Cyanides being one example of those.)
With the proper choice of base material, say a graphite-filled coating,
cyanide-based plating baths offer no advantages, and their very existence
is inconsequential. Baths that instead contain a little sulfuric acid
allow far greater current densities, and will produce a smooth, shiny, and
durable plate. I use safety glasses and wear old clothes, as tiny splashes
will eat holes in your clothing after they're washed, even though the
acid is very dilute. I also keep the tank
covered while plating, as a good hefty current will have the article
being plated in heavy effervescence, and little droplets will otherwise
become airborne, and would be irritating to breathe.
> There was also some talk against nickel-plating because of the posibility
> of nickel carbonyl buildup. That would be very toxic too. I guess you
> better avoid experimenting what happens under arc conditions.
It's the nickel-carbonyl that's "so poisonous it is hard to beleive". I'd
estimate it at perhaps 2 orders of magnitude more poisonous than cyanides.
The hazards of handling cyanides are probably similar to the hazards of
Tesla Coiling. In both cases, you learn the hazards, you develop safe
procedures, and you follow them religiously, or you die. If anything, the
problems of working with high voltage discharges are more unpredictable
and carry more surprises, so if I were afraid of anything dangerous, and
I were forced to either work with a cyanide solution or a Tesla Coil, I'd
be more likely to work with the cyanide. Both can readily kill, however.
Still, when talking about dangers in a hobby that's already dangerous, it
seems unfair not to at least give a relative feel for the difficulty of
managing the risk. As Tesla Coilers, most of us have decided that a
certain level of risk is acceptable, after all. Some, myself included,
will be comfortable with the risk of handling cyanides, provided that
the right procedures are understood and always followed. I'd be almost
certain that no one here would want to mess with nickel-carbonyl. It's
evil.
By the way, I was the one who originally brought up the nickel-carbonyl
concern, and I should point out that this is only speculative at present,
although it's worth looking at seriously. The problem is not with a
"buildup", but with the material vaporizing and being breathed. (It's an
easily vaporized liquid -- the heat from a discharge could do so easily,
if it were there in the first place.)
My concern was based on concern by chemists who work in the pyrotechnic
field, concerning nickel-carbonyl. They have speculated that nickel, and
CO2, in the presence of certain hot flames, could produce this toxin, and
as a result, many possibly interesting pyrotechnic effects using nickel
are not being explored. In Tesla Coiling, we have high temperature plasmas
in an electric discharge containing atmospheric CO2. Emitting such a
discharge from a nickel-plated surface introduces the same starting
materials in a high-energy environment. If the toxin were produced, it
would be in minute quantities, but this stuff is frighteningly toxic,
again, in a whole different world from cyanides. Also, we tend to stand
much closer to our operating Tesla Coils than pyrotechnists stand to their
flaming creations (usually ;-).
Is it *really* worth the concern? I dunno -- how lucky do you feel? I'm
not going to be the one to test it out, with other options so readily
available. But I'm not a chemist, yet I do greatly respect the opinions
of some chemists who've considered the possibility, in a different field.
Sad to say, I bumped into one of those chemists at a pyrotechnic
convention this summer, and I suppose I should have proposed the electric
discharge scenario to him. As it turned out, I was there with my teenage
daughter who's interested in chemistry, and as you might expect, we
instead discussed colleges. Ah well...
Wes B.
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* wesb-at-spectra-dot-net * "It's a magical world, Hobbes ol' buddy... *
* * ..Let's go exploring." - Calvin *
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