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Lead vapor

#27485

Lead vapor | 4 March, 2004

Lead melts at 340C and vaporizes at 1740C (at least someone told me that)

63/37 tin/lead melts at 183C, so does anyone know at what temp the lead will vaporize in this alloy or is it the same 1740C?

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RDR

#27493

Lead vapor | 4 March, 2004

I don't have a clue, but I am really curious as to the purpose of this thread. Did you have some boards come out of an oven that were vaporized and you are curous how hot they got!! OR are you trying to "go lead free" just kidding.

Russ

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pdeuel

#27494

Lead vapor | 4 March, 2004

Russ, Thanks for the laugh. Glad to know some of you still have a sence of humor. I also could not figure out the reason for this thread. I will hadzard a guess that melting point of lead with aloy would not be diferant from melting point of lead by it'self. I would guess that lead would vaporize leaving alloy behind. I do know that vaporazition of some chemicals remain virtually the same when combined with other chemicals. Lead vaporizes at the tempurature lead vaporizes. I assume that mixing with alloy would not change this much.

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#27496

Lead vapor | 4 March, 2004

Alloying lead does not affect its vapor temperature. As you and others mentioned, the vapor temperature is well out of the range of your processing temperatures.

Some people concern themselves about potential health hazards of lead by thinking about inhaling lead vapor. This is unfounded. The concern should be the potential for inhaling the lead oxide / sulfide dust that is an element of dross. That's why: * Operators doing maintainance on the wave need to use proper gear and be educated. * Companies should provide proper equipment, such as a down draft table. * Annual hazardous material monitoring should include wave operators. * Dross pots require special handling.

Here's more on lead: http://www.encyclopedia.com/html/l1/lead.asp

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#27506

Lead vapor | 5 March, 2004

Thanks Dave. The purpose is to educate our employee's. Although I dont think lead vapor is an issue in our facility, I would like to be able to back it up rather than just say "don't worry about it".

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#27508

Lead vapor | 5 March, 2004

OK, if that's the point of concern, use the boiling point of solder as your starting of your conversation. You can find this temperature on the MSDS [from your solder supplier] for the alloy you are using. Expect to find a value on the order of >1300*C.

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Ken

#27515

Lead vapor | 5 March, 2004

I have had OSHA strap accumulative "sniffers" onto wave operators and maint. tech's. THe sniffers collect air bound particulates and trap them into a filter. Later the filter is analyzed and an operator exposure rate is determined. They also will lay doen tack strips and collect "dust" and particles that will naturally settle out on top of machinery and such. Additionally, they will measure effectiveness of hand washing by performing a pre and post wash hand "sample".

Our people are WELL within recommended regulatory guidelines. Canister respirators should be mandatory for de-drossing!

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#27520

Lead vapor | 6 March, 2004

We think that's a good idea. We bring in a company that monitors various people in the shop for lead, just like Ken does, once a year as an element of our plant monitoring program.

Ken do you run the test yourself? If so, what: * Equipment do you use for testing, analysis, etc. * Conditions are necessary for analysis * Etc

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Bryan

#27522

Lead vapor | 6 March, 2004

Hi, everyone knows that we will soon phase into Lead free process.would it neccessary to waste so much money for such a lead content monitor?

Bryan

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Ken

#27523

Lead vapor | 6 March, 2004

We outsource those services. In cases like this I think independent objective analysis is important. We also outsource respirator physicals and fitment certifications.

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Ken

#27524

Lead vapor | 6 March, 2004

I think it is a good idea to "waste" money on this analysis. Especially if you phase in a SAC wave alloy. Silver is not toxicity free....and lead free waves can dross 3 to 5 times faster than SnPb alloys. This produces a greater potential for airborn inhilation due to increased frequency of de-drossing the pot.

I have a lead free wave process. I treat it the same as tin / lead (with regard to respirators)....plus the wave ops switch machines frequently and it truly is simpler enforcing one safety standard.

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Bryan

#27525

Lead vapor | 6 March, 2004

Ken, So your sniffers can deal with not only lead content drosses ,but also other dross like silver etc..if yes,it'll be much neccessary to employ such a sniffer for further analysis. thanks

Bryan

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