From: bobd@magnus.acs.ohio-state.edu (Bob DeBula)
Newsgroups: rec.guns
Subject: Re: bullet casting residue
Date: 1 Sep 92 20:32:41 GMT
Organization: The Ohio State University

In article <012CDEEC047FE01E46@VXC.UNCWIL.EDU> PATE@VXC.UNCWIL.EDU (BILL PATE, ADMIN. SERVICES, PATE@VXC.UNCWIL.EDU) writes:
#
##BTW, I think I may have had a slight acute lead toxicity episode...
##I was trying my first lead casting with an electric bottom pour
##pot and think I had it too hot (got some yellow powder forming
##on the top).  The next day I had some diarrhea, mild headache,
##sinus discomfort, and generally felt odd/lousy for a couple of days.
##
##What was the yellow powder, lead oxide?  Why did it form?
#
#Your experience sounds like the effects welders experience after
#welding or cutting galvanized pipe.  The zinc coating on the metal
#leaves a yellow residue and creates a white or yellowish smoke.
#

Zinc is an *evil* contaminant of lead. It basically destroys
the castability (flow qualities) of "normal" lead alloy (i.e. lead,
tin, antimony, arsenic). I might guess that a yellow
contaminant would be sulphur or a sulphur compound of
some sort (but I am by no means certain of this).

Basically, flux the pot, if it (the yellow stuff) goes back
in solution, try casting it, otherwise scoop it off the
pot and dispose of it. If you notice that the metal doesn't
flow nicely to fill out the details of the mould, then the yellow
stuff was bad & should have been scooped off when it came to
the surface :-). I believe load oxide is white incidently
(just to judge by the ancient lead I've seen sitting in less 
than ideal storage conditions).

Doubtful that you experienced lead poisoning in this brief
interval, *but* all sorts of other things which are
not healthy can also occur when casting. Make *sure* you
are in a *well* ventilated area (I cast outside on nice days
and stay away from the vicinity of the pot while the lead
is melting). Wear goggles. Wear *heavy* leather gloves
(i.e. *not* driving gloves). Wear a heavy shop apron if
you've got it. *Do not* habitually snort the air over
the pot. Wear a hat (two reasons, it keeps the sweat out
of your eyes and it will give some protection if the pot
evacuates in the upward direction (i.e. lead "rain")).
And lastly (I *cannot* emphasize this enough) AVOID WET
LEAD (or lead with rocks in it). 

Molten Pb + H2O = BOOM

Molten lead in a lead pot plus water (even a fractionally
damp recovered bullet or a damp piece of lead) can result
in an explosion. If the piece of lead manages to sink
substantially in the pot before the water vaporizes, it
will blow the lead above it out of the pot & upwards.
I generally add my first batch of lead to the pot, turn
on the heat & leave the vicinity. Try to make sure your
lead is reasonably dry (no dew or dampness) before you
start. When adding lead, I lower it in with a spoon (leather
gloves remember?) *slowly*. It will usually hiss. This
is the water you couldn't detect being vaporized. When
I have the additional lead in, I depart the immediate area
& give it a chance to get up to temperature with the rest 
of the pot. I come back in a few minutes, skim any small
rocks/pebbles which have floated to the surface (seems to
*always* occur with range pickups that you miss a few
small rocks/pebbles -- part of why you vacate the area while 
the lead melts), and then flux (do *not* skim all the gunk
off the top of the pot before fluxing, just the obvious
junk like rocks/pebbles and old bullet jackets). Fluxing
will tend to make the good things (tin oxide, whatever)
go back into the alloy. Once you're done fluxing, go ahead
and scoop the reminder of the garbage off (fluxing should be
done on a regular basis).

Fluxing can be easily accomplished (and may indeed be in the
same league as a superstition amongst casters) by adding a pea sized
lump of alox (beeswax based bullet lube) to the pot 
(*carefully*). Then, once the beeswax (parafin, whatever 
you use) has spread over the surface of the pot, the common
practice is to ignite it. Then skim off the dross which
remains. 

Lead can contain contaminants which can form interesting 
(and deadly) gases. One common mistake which comes to 
mind is using car batteries for casting. Modern car
batteries contain calcium (maybe I'm thinking cadmium,
it's been too long since I read the article) and lead
*must* be assumed to contain arsenic (it is a very
common and not all that undesirable contaminant of lead).
A chemical reaction can take place and form a deadly
gas (commonly used to kill rats). I forget what the
gas is (I can look it up later at home). This and
other interesting details may be found in the Lyman 
cast bullet handbook. I would read through a work
like this before I cast (I will read it before I cast
again since I'm starting to forget import details).

Sorry if I got long winded, but casting can have pretty
serious and adverse consequences if done improperly.
I realize that the posters may already know these things, but
I figured it was worth repeating for any lurkers who
may want to try their hand at casting.

Above all, obtain & read a good book on casting (such as Lymans)
thoroughly before you begin casting.

Of course, I disclaim all responsibility for following my
advice/blatherings and strongly recommend that interested 
parties obtain and read a book on the subject prior to any casting.
This last bit is of course to satisfy the minions of a lawsuit
happy society (as represented by such firms as "Dewey,
Fleesum, & Howe").


(That "Dewey, Fleesum, and Howe" law firm name I borrowed
from an old "Three Stooges" episode :-).

-- 
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              Disclaimer: These are my views, not the U's

        "If it's in the paper it must be true!" --- D. Doright