[TheForge] Speaking of scrap...

[Saint Phlip]

This is the note from Rob- it went to EKMetalsmiths- didn't realize that you
guys hadn't gotten it on TheForge.

Phlip

The US Army investigated the use of Cadminum as a chemical warfare agent in
WW1. The determination was that sublimation at average room
temperature provided inefficent delivery. Both heating and  exposure to an
enriched oxygen environment (creating cadmium oxate and oxide gasses)
increases the danger of the material. In 1996 the US Navy had two divers die
from use of cadmij\um plated fasteners in the flow areas of thier
regulators. Just because somthing is in common use doesn't mean it is safe.
The manufacturer is betting that average air interchange will be sufficient
to prevent exposure at toxic levels. Cadmium plated fasteners and electronic
components are in the excluded materials list of the Submarine Atmosphere
Control Manual.

Rob Myers
USN retired


On 5/28/06, Saint Phlip <phlip at 99main.com> wrote:
>
>
>
>  On 5/28/06, Mike Porter <michael.a.porter at comcast.net> wrote:
> >
> > Phlip,
> > I agree that cadmium presents a great danger when heated past its
> > boiling
> > point, which is 1409° F.
>
>
>  Mikey- water boils at 212 degrees. Does this mean it's totally inert at
> room temperatures? Of course not.
>
> > When cadmium containing filler alloys are employed
> > in brazing, they should only be used with proper powered ventilation
> > and an approved respirator.
>
>  Approved specifically for cadmium.
>
> > The operator must also take the precaution of using heat monitoring
> > devices (usually Tempilstiks(r)), and be careful to avoid overheating
> > the part surface with a torch by using soft brush flames and constant >
> torch movement.(Taking supplemental zinc daily is also recommended
> > when a worker is exposed to any cadmium fumes or dust).
>
>  If they live that long. It'll help, with a sub-critical dose, but not
> only does it have a very low critical dose, but even the zinc will do very
> little but let you die more slowly.
>
> It's rather similar to the iodine kept on hand for large doses of
> radiation exposure. Ain't nothing gonna cure it, just slow the process down.
>
> >You are correct that general hot work on cad-plated materials could be >
> considered as a sign of insanity, and will generally result in the
> > immediate collection of a Darwin award.
>
>  As part of his training, Rob not only saw the movies of the divers dying
> as the rescuers tried to save them, but the autopsy pictures of their lung
> and liver tissues.
>
> And, the cadmium screw heads (3 10s, approximately) were at a temp of
> roughly 65 degrees. The O2 was up at about 35%, from normal atmospheric
> percentages of 21%, at a pressure of several (it varied) atmospheres. That's
> well below the boiling point of cadmium, but the high oxygen content and
> pressure increased the sublimation effect considerably.
>
> > However, the only form of cadmium with which I'm familiar is hot-dip
> > surface plating, which is similar to zinc in color when new, but which >
> quickly oxidizes to a gray leaden appearance. Could you persuade
> > your roommate to go into this "brass and bronze" appearing variety a >
> little further?
>
> > Mikey
>
>  Read Ries' commentary- he explains it well. And, btw, the note just
> previous to this one was written by Rob. He just didn't think to sign it.
>
> I've run into the cadmium plated fasteners- just didn't know what I had,
> until Rob and I had this discussion. As you can imagine, I'll be checking
> over my various bits of scrap.
>