cleaning keyboards in the dishwasher

Chuck Guzis cclist at sydex.com
Fri Jan 13 12:58:52 CST 2006


On 1/13/2006 at 8:38 AM Sridhar Ayengar wrote:

>Chemically, a metal behaves very differently when in a compound.  Sodium 
>metal has a tendency to react violently with water.  A chunk will fizz 
>violently.  Ground sodium in cold water will explode, due to the higher 
>surface area.  However, if you compound it with chlorine, you get 
>ordinary table salt, necessary for life.

The problem with many of our hazmat regulations--particularly when it comes
to heavy metals, is that they rarely take into account the form the metal
is in.  For example, if you have amalgam fillings in your teeth, you have
mercury that's been placed in your body (silver amalgam is a solution of
silver in mercury).  In this form, the mercury's not particularly reactive
with the substances inside your mouth and the danger is minimal.  Yet the
amount of mercury in one filling, combined with two other harmless elements
(hydrogen and carbon) to make dimethyl mercury, is sufficient o kill you
and a couple of your friends.  Add a little sulfur and some sodium,
rejuggle the molecular structure and you've got thimerisal, a preservative
used in vaccines and injected right into your bloodstream.

The EU RoHS has me in a tizzy because the regulations are beginning to
mandate that lead be removed from solders used to assemble brass musical
instruments.  Well, the substitutes don't flow as nicely and it's much
harder to make a strong joint.  I've seen instruments that have come from
the top German manufacturers that have cold solder joints.  But a musical
instrument has a very long life (50 years and longer isn't unusual); the
solder is well contained and doesn't leach from the joints during use, so
where is the harm?  We're not talking about mobile phones with an average
life of less than a year here.  My oldest (and still-played)  tuba dates
from 1895.

Cheers,
Chuck





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