Hi Gordon. You wrote:
> Lead!! A good example of using lead is solder. Solder is used > everywhere without any problem. No worry! Solder in itself seems safe enough, though I wouldn't sprinkle it on my salad.. Isn't there a problem with lead vapour? The soldering operation melts solder (a eutectic alloy of lead, tin. and often antimony, copper, aluminium, silver, and maybe some others) at anywhere between 300 and 470 deg C. At these temperatures the vapour pressure of lead vapour is about 0.5mm Hg. Isn't this considered a bit dodgy to a full time operator? The argument that it stops the inside of a lung rusting no longer has credence, I fear. I got the impression that Michael Jamisons original question about lead in cables may have been related to the joining operation, e.g. spot welding (lead boils at 1750 deg C I think, VP=1bar). Leaded steel bar, which is easy to cut and improves finish, is dissallowed for the same reasons - lead vapour emission during the turning operation, but totally safe thereafter as long as you don't weld it, or eat it. Chris Dupres EMC Specialist. VG Microtech. [email protected] tel +44 (0) 1825 761077 fax +44 (0) 1825 768343 'Opinions expressed are personal, not necessarily Corporate'
