[TheForge] Speaking of scrap...

[Mike Porter]

Phlip,
I agree that cadmium presents a great danger when heated past its boiling
point, which is 1409° F. When cadmium containing filler alloys are employed
in brazing, they should only be used with proper powered ventilation and an
approved respirator. The operator must also take the precaution of using
heat monitoring devices (usually Tempilstiks®), 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). 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.

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

-----Original Message-----
From: theforge-bounces at mailman.qth.net
[mailto:theforge-bounces at mailman.qth.net] On Behalf Of Saint Phlip
Sent: Sunday, May 28, 2006 7:43 AM
To: theforge at mailman.qth.net
Cc: EKMetalsmiths at yahoogroups.com
Subject: [TheForge] Speaking of scrap...

My roommate, Rob, recently retired from the Navy, wanted to pass the
following warning along, since so many of us mess with scrap.

We're all, I hope by now, familiar with the dangers of zinc, which, over
time, will kill you. Unfortunately, there's another material which is far
more dangerous, as in if heated, it will give off gases which will make you
dead, as in RIGHT NOW. And, it's not only becoming more and more common as a
plating material for steel fasteners, but it also looks very like other,
safer materials like brass and bronze.

The material I'm referring to is Cadmium. While reasonably safe in cool
applications (it doesn't start to gas off until 90 degrees F), it's such a
dangerous atmospheric contaminant that the US Navy doesn't allow it aboard
their submarines.

In color, it's rather golden, with an inner reflection of blue, green, or
purple. After some mild heating, the color is, as I said, very like brass or
bronze. It's being used more and more these days, because it's even cheaper
than zinc.

Please, if you use scrap for forging, as I do, and as most smiths do at some
point or another, make sure you know what you have. After all, dropping dead
means you'll NEVER finish that dream project ;-)

-- 
Saint Phlip

Don't like getting old? Beats the Hel out of the alternative.

The purpose of life is not to arrive at the grave, a beautiful corpse,
pretty and well-preserved, but to slide in sideways, thoroughly used up,
totally worn out, proclaiming, "Wow! What a ride!"