Newsgroups: rec.crafts.metalworking
Subject: Re: sources for metal to cast?
From: John De Armond
Date: Thu, 06 May 93 22:11:41 GMT

rmm20@ccc.amdahl.com (Robert Mitchell) writes:
 
>>My dad used to cast his own scuba diving weights.  He found lead at the local
>>hospital.  It was from casings used to transport radioactive material.  Try
>>the radiology or cancer department of your local hospital.
>>--
 
>Somehow this does not seem like such a good idea.
>Doesn't lead shielding radioactive material become (low level) radioactive?
 
No!!  Geez, what'd you do, sleep through physics class?
 
To the original post, lead shipping casks may or may not be pure lead.
It is common to fill steel-cased casks with pure lead but these are
rarely surplused.  The cast lead containers are typically cast from
hardened lead to make them more resistant to handling damage.
 
John

Newsgroups: rec.crafts.metalworking
Subject: Re: sources for metal to cast?
From: John De Armond
Date: Thu, 06 May 93 22:30:55 GMT

ebo@algodones.unm.edu ((E.A. Bouffier - John David)) writes:
 
> Please, someone correct me if i'm wrong but, what is the half life of the
>radioactive materials used in medical procedures? I will note now that it is
>unlikely that the hospitals would let loose of highly contaminated shielding
>material, but why don't you take a stroll down one of americas costlines (or
>read about them if you are out of the country) were some hospitals have flushed
>syringes, etc., etc., etc., down the toilet to forgo the desposal costs.
 
>  If I are going to take this suggestion, I would also take a giger(sp?)
>counter and some descresion with me too. Have someone show you how to read one,
>and what the readings really mean. I would be even more conserned about
>breathing radioactive lead oxide particals than I would be about just the lead
>oxide - which is in itself quite dangerious.
 
>  Causion... please think this one through...
 
The ignorance contained in this post makes me sick.  And from an .edu site to
boot.
 
The half-life of the radiopharmaceutical is irrelevant.  It never touches
the shield.  Radiopharmaceutals are sterile and are packaged as such.
Additionally, DOT regulations (7A) require the contents to be packaged such
that if the primary container fails, all the contents are contained in
the secondary packaging materials.
 
Radiation does NOT make other objects radioactive.  Only neutrons can activate
elements.  Neutron emitters are not found in the radiopharmaceutical labs.
Even if they were, lead is not activated to any great extent so
your phobia regarding "lead oxide particals" (SIC) is just that - a phobia.
The most common radioactive isotope of lead, PB-210 is in the decay
chain of uranium, radium and thorium and is NOT an activation product.
 
Oh, and the device is a "Geiger" counter, you should be "concerned" and
lead oxide is "dangerous."  Maybe you should show some "discretion"
and learn to spell and learn some elemental physics before your next post.
 
What a bozo.
 
John

Newsgroups: rec.crafts.metalworking
Subject: Re: sources for metal to cast?
From: John De Armond
Date: Sat, 08 May 93 02:23:05 GMT

ebo@algodones.unm.edu ((E.A. Bouffier - John David)) writes:
 
>I asume that I was not clear on this one. I was refering to the lead oxides
>produced during the melting process. As part of my background... I grew up in
>a family of potters and helped out in the shop from about the age of 7 or 8.
 
good for you.  We weren't talking about pottery so that is irrelevant.
 
>since what little experience I have with radioactive materials come from
>some of my friends who are/were employed at Los Alomos Natl. Labs, etc.
>and were also personally envolved with the Mexican steel incident mentioned
>by a previous poster, my "concern" may be a little out of place.
 
I'm a health-physicist by profession.  I have personally been involved
with any number of incidents involving radioactive materials over the
course of my career including the Three Mile Island recovery.  As such I am
less than impressed with your wild claims based on what you may have heard
from a friend.  The mexican steel incident, just like any number of other
similar ones, have nothing to do with the topic of salvaging lead from
radiopharmaceutical shields.
 
>I understand that these radioactive materials are somehow different from
>radiopharmaceutals,but I have already confessed my ignorance on the subtilties
>of the subject and asked for corrections were I am wrong. Thank you for that.
>But this I feel perfectly justified in saying:all of the government regulations
>does not keep accidents from happening, or materials from being improperly
>disposed.
 
So based on zero knowledge of either the isotopes, the half-lives,
the hazards involved or the likelyhood of "accidents", you assert without
any qualification or reservation that the shields should not be used
because they are contaminated or else the rank radiation protection novice
should take a "giger meter" and try to second-guess the professionals.
When challenged, you base that assertion on 3rd hand knowledge of a mexican
contamination event.  WOW!  I'm impressed.
 
>There once was a time, many years ago, when I could ask around and
>probably have gotten some "hot" material for a demonstration of just how easy
>it is to get ahold of contaminated materials. I will not attempt this now so that
>I don't get any one in trouble, or do you not believe me on this one.
 
Still trivial to do.  I have a large collection of common consumer items that
are radioactive.  Start with Coleman lantern mantle.  Or for about $30
you could order your very own set of radioactive lab sources from The
Nucleus in Oak Ridge, TN.  All perfectly legal.  And all totally
irrelevant to your oringinal claim regarding lead shipping casks.
 
I'll give you a little tip.  When you suspect something about which
you have no real knowledge, the way to find out is to post the something
as a question.  If you had asked if the shipping casks could be radioactive
because of what was shipped in them, I or someone else with similar
qualifications would have answered you.  As it is, you opened yourself
up for a flame by asserting knowledge you didn't have.
 
John

Newsgroups: rec.crafts.metalworking
Subject: Re: Radiation (wasRe sources for metal to cast?)
From: John De Armond
Date: Sat, 08 May 93 06:28:56 GMT

kopfj@bert.Tymnet.COM (John Kopf, X6305) writes:
 
[Sure would be nice if you found your <Enter> key every 80 characters or so]
 
>The bottom line is that containers (such as lead "bottles") may be
>contaminated by absorbing some of the radioactive material, but are unlikely
>to be dangerous because they have been exposed to radiation.
 
Considering that lead cannot be activated by any neutron flux found outside
reactor cores or very high power accelerators, we can change that "unlikely"
to "never" and dispense with that worry.
 
>A radiation monitor can determine if a material is contaminated...if you *do*
>get lead containers from a hospital, the hospital can probably check it out
>for contamination before-hand...more likely, they will treat these as
>contaminated without checking and dispose of them according to hazardous
>waste rules.
 
Isotopes shipped in disposable casks are overwhelmingly Iodines, Technicium-99
and Xe-133.  All are very short lived isotopes.  I-131 has the longest half-
life at 8 days.  Now I won't speak for all nuclear medicine departments
but for the several hospitals I have consulted to, it is routine standard
practice to pile the disposable casks in a "decay room" for a month
before release for disposal.  5 half lives is considered to be totally
gone so 30 days handles them all.
 
>A greater danger is a container that is NOT empty...there have been
>occasions where these have "gotten loose", and caused some
>problems (like death).
 
Nope.  Any truly hazardous isotope is shipped in much more complex,
rugged and fire resistant DOT-7A qualified steel-encapsulated containers
that are never disposable.  My nuclear equipment company used to make
DOT-7A containers.  A 100 Curie Kr-85 container (the smallest we made)
cost well over $2000, was completely encased in steel so that if a fire
melted the lead it would not run out, withstood a 100 ft drop onto
concrete and weighed a couple hundred pounds and was hydrostatically
tested to 2250 psi (even though the gas was shipped under a partial
vacuum.) Rest assured no hospital is going to turn something like this
over for disposal to someone who wants to melt the lead out.  Anything
that comes in disposable unencapsulated lead casks is reasonably
harmless.  The cask is used to meet DOT and NRC regulations for package
surface radiation levels that are set just a bit over background.
 
John

Newsgroups: rec.crafts.metalworking
Subject: Re: lead poison
From: John De Armond
Date: Wed, 27 Apr 94 20:58:29 GMT

barry@grian.cps.altadena.ca.us (Barry Workman) writes:

>The most
>common source of lead injestion in the world today is
>lead crystal.  If you decant a wine into that fine
>crystal decanter, you will have lead leaching into the
>wine within 5 min. of the decanting.  Scary isn't it.

You were doing pretty good until you got to this part.  Lead leaching
from crystal is mostly theoretical and can only be detected in highly
acidic liquids stored for LONG (as in months or years) periods of time.
Even tiny amounts of leaching, as from concentrated acid in contact
with leaded glass, results in obvious blemishing.  No blemish, no leaching.
Even the theoretical concern with leaching is a non-issue today, because
all major mfrs of crystal tableware now coat the inside of liquid vessels
with an invisible silicone polymer that completely blocks leaching.

It is impossible to characterize a "most common source" of lead because
the sources vary according to locale.  In the US, the traditional leading
source of chronic exposure has been leaded gasoline.  That exposure path
is almost gone and now leaded pigments dominate.  In order for lead
to be absorbed, it must be present AND must be in a bio-available form.
The lead carbonate that forms as lead paint decays is very bio-available.
Other common lead compounds are not.

John

From: John De Armond
Subject: Re: Casting lead in sand mould
Date: Fri, 15 Jul 94 01:03:45 GMT

brzozoww@mycroft.endicott.ibm.com (Wesley Brzozowski) writes:

>In article <CswFKH.KG5@uicc.com>, neidorff@uicc.com (Bob Neidorff) writes:
>|> 
>|> 
>|> Please, before buying lead or starting into a lead casting
>|> project, SERIOUSLY INVESTIGATE the health risks involved.
>|> Heating lead to the melting point WILL CREATE LEAD FUMES.
>|> Lead vapors which are inhaled can cause LONG TERM MEDICAL
>|> PROBLEMS, including BRAIN DAMAGE.  Lead can also be absorbed
>|> into the body other ways.
>|> 

>I'm not disagreeing or anything, but I'd really appreciate a reputable
>reference on this. 

...

>Again, I'm not disagreeing with the assertion made here, but
>a reference from a reputable, non-chemophobic publication or organization would
>be very helpful here.

I'll disagree.  What Bob said is unmitigated bullshit, and that's the nicest
thing I can think of to say about it.  The stained glass industry is more
than a little bit interested in this topic.  Considering that most 
members of this class are non-scientific artists and not scientists, they
tend to be a bit chemophobic.  Nontheless, some scientific work has been
done in this area.  One can consult any of the industry magazines such
as Professional Stained Glass for more details.  Among the findings,

*	The smoke from molten lead contains NO, that is, NONE, lead.  The
	smoke consists of flux and organic contamination byproducts.  This
	includes soldering smoke as well as lead pot smoke.

*	The only common form of lead that is readilly bioavailable is the lead 
	carbonate that forms as lead oxidizes in the atmosphere.  Common 
	white lead oxide has very low bioavailibility until it reacts with CO2 
	in the air to form the carbonate or is eaten.  Not coincidentally, the 
	only glass artists who showed notable quantities of lead in their 
	blood were the ones doing lots of restoration involving working
	with old, oxidized lead.

*	There was almost no lead in the blood of rank and file glass artists
	who work with new lead, solder, etc.

One can also consult with SAAMI for work they've done relating to lead
and the shooting sports.  

It's really a shame that the sky-is-falling, chemophobic idiots like Bob
have to continually stick their heads up out of the ooze to regurgitate this
crap that they've heard in the popular media.  It not only encourages 
chemophobia but also obscures the real hazards.  Common sense should 
apply here as with all other hazards.  Common sense says don't eat around
lead nor put your hands in your mouth and don't stir up great clouds of
oxidized lead.  Other than that, cast away.

BTW, regarding mold materials for lead, common ordinary plaster of paris
is about as cheap as sand, sets fast, carries detail very well and 
can stand the temperature involved with molten lead.  In using it as
a glass mold material, I've found it to hold up well up to about
1200 degrees F.  Beyond that it gets brittle and tends to crumble.
Mixing chopped fiberglass in with the mix greatly increases the hot 
strength.  Mixing plaster of paris half and half with silica flour 
enables the stuff to hold up to over 1600 degree heat.  Beyond that,
a 50-50 mix of hydrocal and silica flour will take the strength to
over 2000 degrees.

John

Newsgroups: rec.crafts.metalworking
Subject: Linos (was Re: pulsating AC)
From: John De Armond
Date: Tue, 22 Mar 94 06:04:53 GMT

ab396@FreeNet.Carleton.CA (Marcel Lemay) writes:

>The only other lino that I'm aware of in this area is in a museum,
>and I'm surprised how many people in this newsgroup, not only
>know about linotypes, but have actually worked on one.

In the 60s my aunt was married to the publisher of the Chattanooga Free-Press
and she was the society editor.  I had the run of the place.  The lino
floor was my favorite place.  They had one whole floor filled with dozens 
of linos supported by a typemetal foundry.  The air used to hang heavy
with machine oil, smoke and lead fumes.  There was a nifty semi-automatic
ingot delivery system that let a lino operator summon ingots from
the foundry and have them delivered via an overhead trolly.  It was an
environment that would give an EPA type apoplexy these days. :-) 

In addition to occasionally getting to set some production type, I used
to write and publish a little one page newsletter for my grammar and jr
high school.  Heady stuff!  :-) I still have some of the type from that
paper.  I'd love to find a functioning Lino machine to set up in my
office just for nostalga's sake. I have my eye on one but I don't
think the owner is EVER gonna retire!

John