Here's the scoop. Liquids much over their freezing point have a small
but increasing vapor pressure.

Take water for example - you are not shocked to hear that room
temperature water puts water vapor into the air.

It is the same with lead. Or mercury, or tin or whatever....

Lead that has melted puts a little vapor into the air - the hotter the
lead, the more vapor.

At the boiling point, the vapor pressure gets as high as atmospheric
and can drive out all the air....

It doesn't take much to impact kids' intelligence.

Brian Whatcott Altus OK

On Mon, 3 Oct 2005 09:59:34 -0700, "Gordon"
wrote:

The boiling point of pure lead is 3180F. The melting point is 621.43F.
Vaporization will not occur at the melting point as you yourself pointed out
with your comment about the microchip industry.
///
"Rosalie B." wrote in message
.. .
"Gordon" wrote:

How does melting lead expose you to lead? There are NO lead fumes


There ARE lead fumes. I once sampled in an old garage where they were
melting lead to make flower arranging frogs (those things with the
spikes in them that sit in the bottom of the vase so the flower stems
don't fall over). The whole place was so permeated with lead that
they could not even tear it down without making it hazardous waste.
Great overexposures to lead.
///
grandma Rosalie

Go to your local lumber yard and buy a plumb bob! They come in different
sizes and materials including lead and brass.
Gordon


"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message
...
Landfall Navigation.

"Courtney Thomas" wrote in message
news
Maybe a fisherman's outlet ?

Hopefully,
Courtney

If you like to know my lead adveture go he
http://www.geocities.com/szczurowski...uary_2003.html
and here
http://www.geocities.com/szczurowski...arch_2003.html

or www.seagoatonline.com and folow January and March 2003 of boat
jurnal


Adam
S/V Seagoat
Courtney Thomas wrote:
Maybe a fisherman's outlet ?

Hopefully,
Courtney

Dave wrote:


On Mon, 03 Oct 2005 21:20:25 GMT, Rosalie B.
said:

It doesn't really matter to the body whether the lead is breathed in
as dust or fume. Both are hazardous.

It makes a great deal of difference, however, to the matter under
discussion. You argue that melting lead in a can over a stove creates lead
fumes. Gordon argues that the temperature is too low to create lead fumes.
The fact that lead might be ingested by breathing dust is utterly irrelevant
to that issue.

Except that lead fume, if it isn't breathed in BECOMES lead dust when
it cools.

What did you think happened to it?

Again, the argument doesn't hold up. The question is whether the temperature
at which lead melts is sufficiently high to create lead fumes. Lead dust is
not relevant unless you assume your conclusion that it is, rather than that
the lead dust came from another source such as, for example, applying a wire
brush or other abrasives to old solder.

The folks that had the contaminated workplace and clothing were in
effect melting lead on a stove. They weren't doing wire brushing or
other operations, so the lead dust must have come from melting the
lead.

While they do wire brushing in radiator shops, they were also using a
propane torch which was also way hotter than usual, so the lead dust
could have come from either operation.

grandma Rosalie

Dave wrote:

On Tue, 04 Oct 2005 17:08:13 GMT, Rosalie B.
said:

The folks that had the contaminated workplace and clothing were in
effect melting lead on a stove. They weren't doing wire brushing or
other operations, so the lead dust must have come from melting the
lead.

While they do wire brushing in radiator shops, they were also using a
propane torch which was also way hotter than usual, so the lead dust
could have come from either operation.

Thus suggesting that Gordon's initial proposition--that melting lead at its
normal melting point doesn't create lead dust--is likely as not correct.

QED

I think it suggests that small amounts of lead in a soldering
operation wouldn't make much lead dust, but that melting larger
amounts (like for pouring into a small mold, even one as small as
making lead shot for hunting) requires more heat and would make lead
dust.

grandma Rosalie

Dave wrote:

On Wed, 05 Oct 2005 00:38:48 GMT, Rosalie B.
said:

melting larger
amounts (like for pouring into a small mold, even one as small as
making lead shot for hunting) requires more heat and would make lead
dust.

More heat, yes. Higher temperature, no. Big difference.

If you have a point of use item like a small soldering iron it isn't
necessary to heat the lead solder up to a higher temperature. But if
you have a larger vessel to get heated up, you are going to have to
use a more heat which will result in a higher temperature at some
places in the pot. And if you use something like a cutting torch, it
will give you more heat and also make things hotter. So more heat
being applied WILL result in higher temperatures than less heat.


grandma Rosalie

Dave wrote:

On Wed, 05 Oct 2005 03:41:42 GMT, Rosalie B.
said:

So more heat
being applied WILL result in higher temperatures than less heat.

I'm afraid your physics is faulty.

I'm not surprised. I've never had any physics. Probably the terms
I'm using are wrong

I know that if I have a lot of something to melt or defrost, I have
to apply heat for a longer time, or apply higher heat than if I have
just a little bit or if the stuff is short and fat (like a turkey)
rather than long and skinny like a french fry (or a coil of solder).

And the part on the edges (like the skin of the turkey) will melt or
defrost first and get hotter than the stuff in the middle (like the
giblets) which are still cold and un melted or un defrosted..

If I heat something up in a pan, the stuff on the edges will get hot
and start to bubble first. It seems to me that the part of a liquid
or a solid that one is trying to liquefy that gets hot first would put
out moisture (in the case of water) or fume (in the case of metal)
while the part in the middle was still getting hot.



grandma Rosalie

Dave wrote:
On Wed, 05 Oct 2005 03:41:42 GMT, Rosalie B.
said:


So more heat
being applied WILL result in higher temperatures than less heat.


I'm afraid your physics is faulty.

So you support Gordon's original claim that there is no harmful
vaporization below the boiling point?

Printed circuit card assembly involves heating a large amount of solder
(60/40) in a large pot with heaters and a pump in the bottom. This solder
melts just under 500F. It is held at 500 by the temperature controller via
the heaters. When the pump is turned on, the solder surges up thru some
screens, out the top of an opening making a solder wave. The printed circut
card is on a conveyer and passes over the wave thus soldering the leads to
the traces. And guess what. No lead fumes! As even Grandma has admitted.
Why? Because the heat is not high enuf!
Now, I don't know the alloy, if any, used in wheel weights and I don't
know the actual melting temp. But I do know it is not high enuf to make lead
fumes.
Are there other dangers? You bet.
Spilling molten solder on yourself could really ruin your day!
Also wheel weights leave behind the little metal clips and lots of dross.
This all floats and needs to be fished out before pouring. Another good way
to get a nasty burn.
So, you do as you see fit and I'll do my thing and why don't we leave it
at that. ')

Gordon
"Rosalie B." wrote in message
...
Dave wrote:

On Wed, 05 Oct 2005 03:41:42 GMT, Rosalie B.
said:

So more heat
being applied WILL result in higher temperatures than less heat.

I'm afraid your physics is faulty.

I'm not surprised. I've never had any physics. Probably the terms
I'm using are wrong

I know that if I have a lot of something to melt or defrost, I have
to apply heat for a longer time, or apply higher heat than if I have
just a little bit or if the stuff is short and fat (like a turkey)
rather than long and skinny like a french fry (or a coil of solder).

And the part on the edges (like the skin of the turkey) will melt or
defrost first and get hotter than the stuff in the middle (like the
giblets) which are still cold and un melted or un defrosted..

If I heat something up in a pan, the stuff on the edges will get hot
and start to bubble first. It seems to me that the part of a liquid
or a solid that one is trying to liquefy that gets hot first would put
out moisture (in the case of water) or fume (in the case of metal)
while the part in the middle was still getting hot.



grandma Rosalie

Dave wrote:
On Wed, 05 Oct 2005 11:47:19 -0400, Jeff said:


So you support Gordon's original claim that there is no harmful
vaporization below the boiling point?


As I said before, please try to follow these discussions more closely so you
won't have to ask silly questions like that.

Without taking a position one way or the other on the merits, I simply
pointed out the logical fallacies in Grandma R's reasoning.


So you ignore the faulty information, which is a serious safety issue,
and criticize someone because they did not frame their story to your
satisfaction. Hmmmm.

The truth is that lead will vaporize at temperatures far below the
boiling point. Using minimal heat (i.e. staying close to the melting
point) is usually safe, but heating to higher temperatures, which is
possible with home equipment, can be hazardous. In other words,
soldering with a 40 Watt iron is safe; firing up the portable blast
furnace indoors to cast large leads is not.