Solder properties? Irons?

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.

chemistry class we had to study something called - heat of vaporization - itwas 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 theboiling, 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 ~~~~~~~~~

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.

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.

Agreed. Particulate lead is a far more likely source of problems, like from grinding it away.

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

Thank you Gene, certainly glad you cleared that up, I'm not nearly so confused on that issue.