Do I have to tin the tip of my soldering iron every single time? + other questions

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dl324

Joined Mar 30, 2015
12,520
Are you guys still kicking this can 8 months later?
The thread was reactivitated by a new user who added some advice on their experience soldering to NASA-level specs for decades and teaching how to solder. I questioned the veracity of the comments about risks of lead fumes when soldering at normal temperatures and asked if the Poster could cite some trusted references.

If anyone can cite references that state the lead fume risk, or lack thereof, I think it would be helpful to us all. The references I have read, and trust, state there is no significant risk of lead fumes when soldering at normal soldering temperatures.
 

dl324

Joined Mar 30, 2015
12,520
About the last topic of this thread, the lead fumes. As I've said already and dl324 has ignored, you don't need to reach the boiling point of a substance at all in order to see some molecules of it vaporize, or go to the air.
I'm not ignoring what you wrote, I'm treating it as someone's invalid opinion.

The characteristics of water are much different than lead and I think that makes your analogy invalid.

If it was valid, we'd all be breathing lead, mercury, tin, aluminum, copper, gold, silver, ... from the air around us; because every metal on the planet would be evaporating whenever it was in liquid form.

Whenever I've seen people working with molten lead, I see them wearing heat suits. But I've never seen them wearing respirators. Same for people working with other molten metals.
 
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kubeek

Joined Sep 20, 2005
5,744
Well all lliquids do evporate, and doesn´t matter if it is lead or water or anything else. However water at 0°C has vapor pressure of 611 Pa and lead has vapor pressure of 1Pa at 700°C. This is a very big difference, which means that at soldering temperatures the evaporation of lead would be very negligible, and you´d have to heat it very hot to get any significant amounts in the air.
Also, the vaporized lead would immediately oxidize and stay in the air as lead oxide.
 

dl324

Joined Mar 30, 2015
12,520
However water at 0°C has vapor pressure of 611 Pa and lead has vapor pressure of 1Pa at 700°C. This is a very big difference, which means that at soldering temperatures the evaporation of lead would be very negligible, and you´d have to heat it very hot to get any significant amounts in the air.
Thank you for that information. I suspected it had something to do with "pressures", but my chemistry knowledge is long unused and I didn't feel like researching the properties to prove the lead-water analogy invalid.

However, if there is scientific data showing the risk of lead fumes from normal soldering temperatures is significant, I'd like a reference so I can read it for myself and modify my soldering technique appropriately.
 

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rambomhtri

Joined Nov 9, 2015
322
I'm not ignoring what you wrote, I'm treating it as someone's invalid opinion.

The characteristics of water are much different than lead and I think that makes your analogy invalid.

If it was valid, we'd all be breathing lead, mercury, tin, aluminum, copper, gold, silver, ... from the air around us; because every metal on the planet would be evaporating whenever it was in liquid form.

Whenever I've seen people working with molten lead, I see them wearing heat suits. But I've never seen them wearing respirators. Same for people working with other molten metals.
No, you missread me, or worse, you didn't read all my message. Here:

"It happens in a natural process, and if you don't believe me, spill some water in the floor and wait 10 minutes. OMG, the water has disappeared.

Was the floor at 100°C?
No.

The same happens with lead when it's melted.

Of course, the amount of molecules going free to the air depend on the substance/element we're taking about, as well as the vapor pressure and many other variables.

I think that in a well ventilated room, these really tiny lead fumes won't affect at all to your health.

This is what I theoretically know, I haven't got a lab to measure all of this a come here with proofs.

So, do lead fumes happen?
Probably, there will be lead atoms flying around.

Is that harm in any way?
I don't think so due to the low concentration."

The analogy is not invalid, the analogy is perfectly fine and I did it so you could understand what I meant. Then I said that all of that depends on the elements/substances we're talking about.

By the way, this process happens everywhere, but no, we wouldn't be inhaling heavy metals, that's a wrong deduction you made. I can guarantee you that after some time, the lead in 100 g of molten solder will be less than the inicial concentration. So small, but it will be. That's what I meant with "It won't affect to your health at all".
 

dl324

Joined Mar 30, 2015
12,520
No, you missread me, or worse, you didn't read all my message. Here:

"It happens in a natural process, and if you don't believe me, spill some water in the floor and wait 10 minutes. OMG, the water has disappeared.
No, I read and understood what you said. It was just wrong.

As @kubeek pointed out, the vapor pressure of water is much higher than lead; so the potential for lead to enter the atmosphere at the pressures and temperatures involved at normal soldering conditions is essentially zero.

Your analogy is invalid. The vapor pressure of water at room temperature is several orders of magnitude higher than lead.

If you were right, we'd all be insane from mercury absorption...
 
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#12

Joined Nov 30, 2010
18,217
The analogy is not invalid,
The analogy is invalid.
The process of a substance going into the air at low temperatures is called, "sublimation".
A tray of ice in my freezer will completely sublimate in a year. I know because I've done it.
A rock laying on the ground will still be there 50 years later. I know because I've seen it.
Some things simply don't sublimate.
Waiting for a lead fishing sinker to disappear into the air is going to be a very long wait!
Not just centuries, eons.
 

Thread Starter

rambomhtri

Joined Nov 9, 2015
322
Soooooooo,

that's why I said "it depends on many factors, including element we're talking about, vapor pressure of it and so on.

My analogy was to make him understand what was I talking about. Indeed, I precisely typed something like "however, the amount of lead getting in the air depends on...".

Anyways, I'm trying to repair a headphones with microphone (TRRS) and it really is a total PAIN in the *** to solder that thing, I swear. As if it wasn't enough, I forgot to put the jack case BEFORE the soldering process, so after I finished doing it, I realize I didn't put the jacket before. So I'm desoldering it. I hate my life, xD.
 

Thread Starter

rambomhtri

Joined Nov 9, 2015
322
Well, is it alright if I WANNA KILL MYSEEEEEEEEEEEEEEEEELF? :mad::mad::mad::mad::mad:

I'm gonna post the result in my other "audio jack" thread so you can see it.
 
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dl324

Joined Mar 30, 2015
12,520
My analogy was to make him understand what was I talking about. Indeed, I precisely typed something like "however, the amount of lead getting in the air depends on...".
OK, but the analogy was so extreme that my intuition and what I could recall about the subject made me discard any notion that evaporating lead could be a problem.

That's one of the problems with information on the internet. There are people who still think Obama isn't a US Citizen, that there was a second shooter on the grassy knoll, and that NASA didn't land people on the moon. Freedom of Speech means anyone can say anything they want, but that doesn't mean it's true.
 
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