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Fumes extraction and dangers from lead/lead-free soldering

时间:04-04 整理:3721RD 点击:
Hello, I have seen a video from weller that mentions that fumes from lead-free solder can penetrate deep in the lungs, deeper than the cigarete smoke. However they do not menntion anything about lead-based solder, that I used for 1-2 decades.

Of course they want to sell their products, but sinse a few years ago, I switched to kester lead-free solder, the standard Sn-96.5, Cu-0.5, Ag-3 alloy, I wonder how serious it is.

A few months ago, I made a homemade fume extraction system. This is not composed of these fancy fans facing away smoke from the face, but of a vacuum pump that sends the smoke outside of the window of the house, using a lengthy flexible tube. The fumes are extracted directly from the iron tip, since I am lucky to use this one ../imgqa/eboard/Antenna/rf-0qdqalznyo3.jpg
I would say a 95% of the fumes are extracted, maybe a bit more. The only fumes that escape from it, are when I move the iron too quickly, or fumes that are produced by heated components, not by the iron tip itself.

Presupposing the above, I would like to know how seriously could one be affected by this situation?
A recent oxygen measurement on my lungs (for another reason) did not gave any warnings. I guess I escaped the risk?

Just a note, after a month of soldering, the tube that puts the fumes out of the house had clear signs of white sand-like material around it, at it's input and output openings. I had to scratch it to open the diameter of the tube again.

In the past at the 80?s age, all companies here in my country that hired technicians, requested a small chest radiography of the lungs ( locally called ?Abreugraphy? ).Based on that, I can only assume that this was due to the fact that the activity with the lead-based solder was admittedly something typically unhealthy

Lead-based solder, has the lead danger. But weller, does not mention in the video anything about lead-based solder smoke, just about lead-free. Should I assume that lead-based solder fumes are danger as well or is it an issue on lead-free solder only (due to the different chemistry of the resin)

Lead poisoning causes a lower IQ and aggression. This has been noticed on the inner city youth since the lead has been removed from petrol (lead tetra ethyl was the additive), they have become less aggressive and brighter.
I am not sure that lead ingestion is a life reducing toxin as the very last English soldier from the first world war (Harry Patch AKA The last Tommy) died at 115 and he worked with lead all his life.
I think that most of the smoke you see is from the flux, so what does that do to your lungs?
Frank

The fumes do not come from the solder- they are produced from the flux. Most common flux is rosin- a gum (plant product)- widely used in electronics work. If done carefully, the fumes have no detectable amount of lead or tin (they do not evaporate at the temperature of the soldering iron). Lead free solders also need some flux (I do not know the exact nature).

The flux acts as a reducing agent and removes the oxide layer. The fumes contain particulate matter (smoke) that are as dangerous as cigarette smoke. Some of the rosin simply boils off and can be recovered by cooling (the deposit on the tubes you mention).

Fluxes used by welders (the thin coating on the welding rods) contain heavy metals. They are far more toxic.

I think you need a much higher temperature than a soldering iron has to make lead fumes. you would need a torch. so you are probably fairly ok for lead. of course you need to wash your hands when handling lead based solders before you eat.

what IS a big problem is the flux fumes. they puff up in a big cloud of smoke, and you breath that stuff in. who knows what type of chemical composition you are breathing in.

My fume exhauster is a 4" diameter flexible metal pipe hooked up to a big exhaust fan that just sucks those fumes outside. I use a wireless switch I found in a woodworking store to turn the exhaust fan on/off when I am soldering. I Just keep the open end of the pipe near where I am soldering. If I clean off my soldering iron tip with tip cleaner, I stuff the tip into the pipe until the smoke stops. just remember to earth ground the metal pipe, as the fan and metal pipe form a type of VanDerGraph generator and make static electricity

Tha problem with this is:
1. you have to solder where the pipe is, which is not very practical when you try to concentrate on the work, or you have to have a big horn above the bentch and lots of air pressure.
2. most importantly you need a hole to be made on the window, or to freeze on winter by having the wondow open. But if I was to have the window open I wouldn't need a fume extraction would I? The much thinner tube that take the fumes directly as they come out of the tip, seems a better solution to me. I have tried both ways.

Most of the fume produced during soldering will condense when cooled and very little of the smoke will remain once the "fume" gets cooled; either by mixing with cold air or just by getting diluted. A part of the fume will not condense; they have the solvent in the flux paste. Unless you are doing production quality soldering on a regular basis, there is no special need to worry. Nevertheless, it is best to avoid the fumes. They are plant gums and contain organic solvents as activators (I do not know the exact details).

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