Solder properties? Irons?

On 5/28/04 9:25 PM, in article ,
"Moonraker" wrote:


"O D" wrote in message
...
Don't know this as absolute fact of lead ingesting , but if you have a
change of state in the lead then you may have vapor being inhaled. When
you go from asolid to a liquid there will be some small form of gas that
is carried in the air stream.

Close.

Matter only has three properties, solid, liquid, or gas. Those states for
every type of matter are attained at very specific temperatures.

Nitpick here - but there *is* a 4th state of matter not normally achievable
without fancy equipment - plasma.

Those temps are modified by adding some other matter to a pure substance.
Similar to adding salt to ice, which lowers the melting (liquification
point) below 32*F. That's why adding tin and (whatever) to lead makes
solder work. Solder is an alloy that liquifies at a temperature lower than
the melting point of the relatively pure lead came. Going from memory,
solder melts at about 425F, and lead melts at 621F. The boiling point (not
melting point) of lead is nearly 3200F, and my soldering iron sure doesn't
get THAT hot.

There are a bunch of solders usually with tin, lead and silver in different
proportions for different melting points. But as you have wisps of steam
wafting from water that is heating up - and ice can sublimate into gas at
lower temperatures - so this can happen with lead - though I am not sure how
this would affect lead infused fumes!

Gaseous states start only at the boiling point, by definition.
Liquification points are much lower temperatures. I think what is actually
happening is that as the lead (or solder) liquifies, small droplets of
molten metal are swept airborne by the vapor of the boiling flux. Given
that the lead came itself isn't visibly melting away, most of the actual
toxcity is likely from the lead in the solder. I believe the spatter caused
by the boiling of the flux is carrying solder droplets airborne.

That is probably right!

"BRENT" wrote in message
.. .
On 5/28/04 9:25 PM, in article
,
"Moonraker" wrote:


"O D" wrote in message
...
Don't know this as absolute fact of lead ingesting , but if you have a
change of state in the lead then you may have vapor being inhaled. When
you go from asolid to a liquid there will be some small form of gas
that
is carried in the air stream.

Close.

Matter only has three properties, solid, liquid, or gas. Those states
for
every type of matter are attained at very specific temperatures.

Nitpick here - but there *is* a 4th state of matter not normally
achievable
without fancy equipment - plasma.

Damn newfangled ideas, anyway! Who in tarnation came up with this notion?
;)



Those temps are modified by adding some other matter to a pure
substance.
Similar to adding salt to ice, which lowers the melting (liquification
point) below 32*F. That's why adding tin and (whatever) to lead makes
solder work. Solder is an alloy that liquifies at a temperature lower
than
the melting point of the relatively pure lead came. Going from memory,
solder melts at about 425F, and lead melts at 621F. The boiling point
(not
melting point) of lead is nearly 3200F, and my soldering iron sure
doesn't
get THAT hot.

There are a bunch of solders usually with tin, lead and silver in
different
proportions for different melting points. But as you have wisps of steam
wafting from water that is heating up - and ice can sublimate into gas at
lower temperatures - so this can happen with lead - though I am not sure
how
this would affect lead infused fumes!

I was thinking about the evaporation of ice... wouldn't that have to do with
relative humidity? I doubt that any metallic solids sublimate into gas
without being attacked by an outside agent. If that were the case, your
gold Rolex would be growing smaller and smaller.

Now, of course, if you put that Rolex in a chamber full of Aqua Regia,
wouldn't the fumes would begin to attack the gold surface and etch the
polished surface? What happens to the molecules that were on the surface?
Are they now airborne?



Gaseous states start only at the boiling point, by definition.
Liquification points are much lower temperatures. I think what is
actually
happening is that as the lead (or solder) liquifies, small droplets of
molten metal are swept airborne by the vapor of the boiling flux. Given
that the lead came itself isn't visibly melting away, most of the
actual
toxcity is likely from the lead in the solder. I believe the spatter
caused
by the boiling of the flux is carrying solder droplets airborne.

That is probably right!

I guess that settles it....unless some know-it-all Canadian has an
alternative theory.

As soon as he "perfects" his economic therory of retailers keystoning their
way into bankruptcy, I'm sure we will hear more pontification about how
lead poisoning doesn't exist and if it does, you got it from picking your
teeth with wire solder or something equally nonsensical.

On 5/29/04 9:19 AM, in article ,
"Moonraker" wrote:

Those temps are modified by adding some other matter to a pure
substance.
Similar to adding salt to ice, which lowers the melting (liquification
point) below 32*F. That's why adding tin and (whatever) to lead makes
solder work. Solder is an alloy that liquifies at a temperature lower
than
the melting point of the relatively pure lead came. Going from memory,
solder melts at about 425F, and lead melts at 621F. The boiling point
(not
melting point) of lead is nearly 3200F, and my soldering iron sure
doesn't
get THAT hot.

There are a bunch of solders usually with tin, lead and silver in different
proportions for different melting points. But as you have wisps of steam
wafting from water that is heating up - and ice can sublimate into gas at
lower temperatures - so this can happen with lead - though I am not sure how
this would affect lead infused fumes!

I was thinking about the evaporation of ice... wouldn't that have to do with
relative humidity? I doubt that any metallic solids sublimate into gas
without being attacked by an outside agent. If that were the case, your
gold Rolex would be growing smaller and smaller.

So *that¹s* why I can't seem to find the thing - must have sublimated! :-)

If it is sublimating - I suppose it is getting smaller - though I have no
idea of the rate!

Now, of course, if you put that Rolex in a chamber full of Aqua Regia,
wouldn't the fumes would begin to attack the gold surface and etch the
polished surface? What happens to the molecules that were on the surface?
Are they now airborne?

I have no idea if they are - though I would imagine that it might form
compounds that are - ?


As soon as he "perfects" his economic therory of retailers keystoning their
way into bankruptcy, I'm sure we will hear more pontification about how
lead poisoning doesn't exist and if it does, you got it from picking your
teeth with wire solder or something equally nonsensical.

Using stranded solder as floss is not recommended - :-)

All my work tables are painted white (you can see the dust). Hepa
vacs. I also have 10 large hepa air cleaners (shop is 2200 sqft).
Seperate storage area for tools etc. Seperate charging (locker room)
and eating room, both with hepa air cleaners. When taking apart old
leaded windows, do it under water (no dust).
For working at home, my guess is that the dust is being carried
through a common air/heating system from the shop to the living area.
Look into better filters for the HVAC system.

Try this link. http://en.wikipedia.org/wiki/Heat_of_vaporization

In chemistry class we had to study something called - heat of vaporization - it
was one of those things that didn't sit well in my head, but the term stuck.
And I believe that you're talking about the vaporization of lead, not the
boiling, or anything.
So the addy above will take you to the place that discusses this topic.

Shirley Gutkowski, RDH, BSDH
"Everbody wants to save the earth - nobody wants to help Mom to do the dishes."
- P. J. O'Rourke
~~~~~~~~~
http://www.dentistry.com/poralhealth_02.asp

"Shirley Gutkowski RDH" wrote in message
...
Try this link. http://en.wikipedia.org/wiki/Heat_of_vaporization

In chemistry class we had to study something called - heat of
vaporization - it
was one of those things that didn't sit well in my head, but the term
stuck.
And I believe that you're talking about the vaporization of lead, not the
boiling, or anything.
So the addy above will take you to the place that discusses this topic.

Actually it is the vapour pressure of lead which is the critical factor.
Using the data from the Rubber Handbook, it works out at 3.09748E-05 mm Hg
at the melting point, which is pretty low by anyone's standards. It is about
46mm Hg at the boiling point.
--
Terry Harper
http://www.terry.harper.btinternet.co.uk/

"Terry Harper" wrote in message
...
"Shirley Gutkowski RDH" wrote in message
...
Try this link. http://en.wikipedia.org/wiki/Heat_of_vaporization

In chemistry class we had to study something called - heat of
vaporization - it
was one of those things that didn't sit well in my head, but the term
stuck.
And I believe that you're talking about the vaporization of lead, not
the
boiling, or anything.
So the addy above will take you to the place that discusses this topic.

Actually it is the vapour pressure of lead which is the critical factor.
Using the data from the Rubber Handbook, it works out at 3.09748E-05 mm Hg
at the melting point, which is pretty low by anyone's standards. It is
about
46mm Hg at the boiling point.
--

I suppose the vapor pressure of Lead would be important if one were working
in an absolute vaccum.

Given that the normal atmospheric pressure is 750+/-mm of Hg, such a
minisicule vapor pressure of Lead has little to do with everyday handling.

"Shirley Gutkowski RDH" wrote in message
...
Try this link. http://en.wikipedia.org/wiki/Heat_of_vaporization

In chemistry class we had to study something called - heat of
vaporization - it
was one of those things that didn't sit well in my head, but the term
stuck.
And I believe that you're talking about the vaporization of lead, not the
boiling, or anything.
So the addy above will take you to the place that discusses this topic.

Shirley Gutkowski, RDH, BSDH
"Everbody wants to save the earth - nobody wants to help Mom to do the
dishes."
- P. J. O'Rourke
~~~~~~~~~
http://www.dentistry.com/poralhealth_02.asp


I'm not sure how you think Lead would get vaporized unless it was AT it's
boiling point? The link you provided defined the "heat of vaporization" as
the AMOUNT of heat required to vaporize one mole of a substance (at standard
pressure) when the substance was at it's boiling point. IOW, the
additional heat required to turn Lead into vapor once it reached the
critical boiling point. The converse of that would be the amount of heat
released into the atmosphere once the vapor cooled and the lead returned to
a liquid form. The "dew point", as it were.

"Moonraker" wrote in message
...

"Terry Harper" wrote in message
...

Actually it is the vapour pressure of lead which is the critical factor.
Using the data from the Rubber Handbook, it works out at 3.09748E-05 mm
Hg
at the melting point, which is pretty low by anyone's standards. It is
about
46mm Hg at the boiling point.

I suppose the vapor pressure of Lead would be important if one were
working
in an absolute vaccum.

Given that the normal atmospheric pressure is 750+/-mm of Hg, such a
minisicule vapor pressure of Lead has little to do with everyday handling.

Agreed. Particulate lead is a far more likely source of problems, like from
grinding it away.
--
Terry Harper
http://www.terry.harper.btinternet.co.uk/

"Moonraker" wrote in message
.. .

"O D" wrote in message
...
Don't know this as absolute fact of lead ingesting , but if you have a
change of state in the lead then you may have vapor being inhaled. When
you go from asolid to a liquid there will be some small form of gas that
is carried in the air stream.

Close.

Matter only has three properties, solid, liquid, or gas. Those states
for
every type of matter are attained at very specific temperatures.
Those temps are modified by adding some other matter to a pure substance.
Similar to adding salt to ice, which lowers the melting (liquification
point) below 32*F. That's why adding tin and (whatever) to lead makes
solder work. Solder is an alloy that liquifies at a temperature lower
than
the melting point of the relatively pure lead came. Going from memory,
solder melts at about 425F, and lead melts at 621F. The boiling point
(not
melting point) of lead is nearly 3200F, and my soldering iron sure doesn't
get THAT hot.

Gaseous states start only at the boiling point, by definition.

Close.

A "gaseous state" for the bulk of your material may start there, but gas
itself does not.

*Boiling* starts at the boiling point, not the release of material in
gaseous form.

The temperature of any object is a statistically determined number that is
related to
the velocity (*average* kinetic energy, actually) of the molecules that are
dancing
around under the action of heat.

This number reflects the *average* kinetic energy, and many molecules will
be moving at
greater or lesser velocities, including some that are moving at
*considerably* greater velocities,
all the way up to and including velocities that allow them to escape the
surface as a gas.

Even at room temperature, some molecules will inevitably be moving fast
enough (with enough
energy) to escape from the surface. You do not have to heat any liquid all
the way to boiling to
release its molecules into the air as a gas.

For a simple example most people will be familiar with, if you leave a
teaspoon or so of water
in a glass at room temperature for 2-3 days, you will probably not have a
teaspoon of water
in that glass anymore. Do you think the water just magically vanished, or
was somehow sucked
into the air mysteriously? No boiling flux here to sweep the water molecules
up into the air,
either. In fact, a teaspoon of *ice*, sitting on your counter-top, is
releasing molecules into
the air, admittedly not very rapidly, but nevertheless it is losing gaseous
vapor as you watch.
(And any objections to this based on the observation that if the humidity in
the room is at
100%, the water doesn't vanish, are misleading because while molecules are
escaping from the
surface of the water, other molecules of water in the air are arriving and
replacing the lost
molecules, so that the teaspoon of water will *not* be the same teaspoon of
water you started
with. In the case of ice, this is restricted to the near surface, but in the
case of water the molecules
are free to diffuse throughout the volume.)

So that it is inevitably the case, among the molecules that are jostling
around (with their random
distribution of kinetic energies) under the influence of heat, even at 0
degrees celsius, will be
plenty that have a high enough velocity to escape the surface.

The boiling point of a substance is its *boiling* point, not the point at
which molecules of
the substance suddenly start drifting off into the air. *That* happens at
temps a lot lower
than the boiling point.

At the boiling point, essentially *all* of the molecules have enough kinetic
energy to escape into
the air (against the air pressure, btw...lower the air pressure and you need
less heat, i.e. a lower
temp.) OTOH, not *all*, but plenty (for a suitable definition of "plenty")
of molecules have enough kinetic energy to escape as gas at lower temps.

Now, *if* heat distributed energy *equally* to all the molecules, you would
have been right to
have concluded that at less than the temperature of vaporization no gas at
all would be released.

Unfortunately, though, it doesnt.

HTH. HAND.

-Gene