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Re: Rubber toroids
From: Harri Suomalainen[SMTP:haba-at-cc.hut.fi]
Sent: Friday, October 24, 1997 5:27 PM
To: Tesla List
Subject: Re: Rubber toroids
On Wed, 22 Oct 1997, Tesla List wrote:
> The laquer is made easily conductive by the addition of powdered graphite
> (I've experimented with mixes of graphite and conductive lampblack, which
Commersially available sprayable graphite (used on tv's for example) is
quite reliable and not too expencive. It should be considered as well
as a choise. Making something similar your self may or may not be worth
the trouble.
> adhering plate. One of my old posts gave some plating formulations; if you
> want good adhesion, just ordinary old copper sulfate solution will tend
> to fall a little short. Commercial plating tends to use a mix of copper
> sulfate and sulfuric acid in the plating bath. While the word "acid" tends
> to frighten a lot of people off, it's once again a matter of knowing the
> materials and managing the risks. Personally, I consider an operating coil
> to be much more dangerous, but we readily manage those risks. When using
Agreed. It sounds bad and should be handled with care. It will give you
nasty burns and does not feel too nice if spilled on you. It will damage
eyes too. As soon as the risks are realized it is safe to handle and
nothing to be afraid of.
> sulfuric acid, you do want things like safety glasses and old
> clothes, though. (When you wash the clothes, you'll see how easy it is to
Also remember the order of mixing: pour sulfuric acid to water. Never ever
do pour water into the acid. It will generate quite a lot of heat and it
may (probably will) be spilled/spached all over. If poured in the right
order it is ok. This is just too easy mistake to make if you just won't
happen to know it.
> spatter droplets of the plating solution; every place a droplet hit your
> clothing will be replaced by a small hole.) It may be possible to plate up
It will make holes to the other clothers too. I definately wash my
lab coat separately to avoid making holes to the other clothes in the
machine at the same time.
> The original posts also contained some severe warnings about using nickel
> plating for something like a toroid, but which some people are suggesting
> now. The discharge from a toroid may vaporize small amounts of metal. While
> copper can be ingested in small amounts (hey, we actually need it in trace
> amounts; perhaps coiling can be healthy? ;-) nickel can do really nasty
> things to you. Worse are some of the incredibly toxic organometallics it
> can form. Given sufficient energy and ordinary atmospheric components,
> nickel can form nickel-carbonyl, a toxin that makes the cyanides
> everyone's been worrying about look like candy. The stuff is vaporized at
I'd like to hear more about the nickel subject. I guess I ought to do some
quick checks at the library too. Any idea of LD50 and ED50?
HCN has LD50 of around 1mg/kg (human, inhaled). (LD50 means half the
subjects killed.) It should be at least handled with great care. It also
seems to have quite low ED50 (effective dose), no idea of the reported
value. From personal true life experience, I'd guess definately below
0.5mg/kg. If you try it out ourself you'll respect the dangers quite a lot
more. You may or may not live to tell about it.
The change is also non-recoverable, the change will be permanent if no
medicine is available. That's why even as low as 1ppm will be dangerous
for you! All toroid platers should definately avoid those too nasty
chemicals IMHO. A chemists opinion.
Anything coming even near that nasty should definately be watched out for.
That's why I'd like to hear more abuot the nickel stuff. I'll report my
findings in the local library too.
However, I'm still not very convinced of the dangers of nickel until
further info has been dug up. That would be too common stuff you know..
I'll still look more into it, just to be on the safe side. Nickel would
be a nice lookin plating you know..
> low temperatures, making the path to ingestion just ordinary breathing.
Samy for cyanides too. Sure, you may look up at the book and say "what the
heck, it boils only at a bit over room temp" but it will still be
vaporized just too easily.
> Now, I don't know for sure wether an electrical discharge to a nickel
> surface will produce nickel-carbonyl, but I personally wouldn't try to
> find out by experiment. The stuff is just too scary to me to think of
I'd assume the risk much more commonly known if it did happen. However,
avoiding the possible risk makes sense too.
> ingesting in any trace amounts, and I'm not particularly worried about
> handling cyanide solutions (though I am particularly cautious when doing
> so). In any case, it might be worthwhile to hold off on the nickel plating
Funny. Most of my co-workers *are* worried even professionals. At least
a non-professional should worry a lot.
> One other item; the use of copper chloride as an electrolyte has been
> mentioned, and while it seems that it should be able to deposit a layer
> of copper just like copper sulfate can, I can also see some problems,
Good point. Anyway, I think suphate is more common,
> which may be the reason it's not used commercially. First, there's the
> problem of using an acid-copper bath to improve adhesion. If we need
> to add acid to get a decent plate for a surface that's punished the way a
> toroid is, the addition of acid to a chloride solution will evolve
> hydrochloric acid fumes, which are quite unpleasant to breathe. The
Yap, unpleasant. Thay will also make everything attacked very badly.
Say you have some iron around. After working for a while with HCl fumes
you'll find it supprisingly rosty. Same for most other metals too.
Not too pleassant.
> second is the fact that a class of chemicals called chlorates are produced
> commercially by the electrolysis of chloride solutions. If any copper
> chlorate is being produced in the process, you could be producing a very
> unstable vat of liquid. I'm not sure how it acts in solution, but solid
> copper chlorate has been known to explode without provocation. Now, I'm
It would make a lot of clorine gas (not too healthy!) if chlorates were
made. They're fairly toxic too and won't feel too good. In a
large-scale production (like a huge toroid) the amount of
chlorine involved could be quite a huge.
Chlorates sure can be unstable. They can be insoluable in the solution too
so they will perticipate out. Quite a few chlorates do that. However, you
can prevent chlorate making by controlling the voltage. I think around
4V or so would be needed for chlorate making. (From the memory, not
checked!) However, everyone with 5V PSU's around can be in risk.
I'd go for sulfates instead of chlorides too. Chlorides can work faster
(or should at least in my opinion) in a non agitating solution. Still,
usually time is no consern. Making better electrodes makes a lot more
change anyway.
> Anyway, anyone interested in this subject might want to look for those old
> postings from a year ago or thereabouts. I think there might be some
> useful information there. In any case, I'm personally very interested in
> seeing people work on this problem again, so keep tossing out those
Me too. I think making nice toroids yourself should be something every
coiler or hv electrician should be able to do!
--
We have phone numbers already, why would we need IP-numbers! -unknown person
Harri.Suomalainen-at-hut.fi - PGP key available by fingering haba-at-alpha.hut.fi