hobby soldering: do you guys go lead-free

Hi all,
I am fairly new to the forum as I've recently picked up an old passion: that of building circuits. I'm starting with some domotics and robot applications - yes I am a computer scientist - and now that I am ready to put the pieces together I've been looking at lead-based vs lead-free solder.

What do you guys use in your home labs?
I've done a little soldering in the past and back then I didn't even know lead was a dangerous metal. Now, the risk of being contaminated with lead is negligible if you wash your hands after your work, but still if there is a safer alternative, I'll be happy to go for it.

From what I have read, it looks like the problem with lead-free solder is that there are a lot more flux fumes and that these are generally more dangerous.

so my question is: what do you guys use? Do you have any equipement to avoid inhaling fumes? Fume extractors? Fans? Masks?

Thanks

Dave

actually the lead oxide can penetrate through the skin but for sure the washing is a good practice. The best Lead-free solder I found is from Balver Zinn. Before this I tried many other solder and all they were awful. With Balver Zinn you don't feel any difference when you solder - smooth, shiny and glossy solders just like you use lead. So there is no sense to continue contaminating your body with lead, especially if you know that lead once came in your body is very hard to be taken away and bones and teeth will suffer for sure.

thanks luben!
But what do you do about fumes? According to some they're even worse of a concern than lead for hand soldering.

I've used a variety of lead free solders both for production repair work and hobby projects. Lead free alloys require higher temperatures and stronger fluxes and strip the plating off of your iron tips much faster than lead alloys. I prefer a 62% Tin, 36% Lead and 2% Silver alloy. It's much easier to work with and produces clean, strong, shiny joints that are easy to inspect. I only use lead free when required and charge a premium for it.

Glutaric and adipic acid fumes from the fluxes used with lead free solder are a significant cause of occupational asthma. You can use a fume evacuation system but most benchtop devices merely redirect and dissipate the fumes in the room.

how about doing the soldering outdoors and/or wearing a mask?

KJ6EAD said:

I've used a variety of lead free solders both for production repair work and hobby projects. Lead free alloys require higher temperatures and stronger fluxes and strip the plating off of your iron tips much faster than lead alloys. I prefer a 62% Tin, 36% Lead and 2% Silver alloy. It's much easier to work with and produces clean, strong, shiny joints that are easy to inspect. I only use lead free when required and charge a premium for it.

Glutaric and adipic acid fumes from the fluxes used with lead free solder are a significant cause of occupational asthma. You can use a fume evacuation system but most benchtop devices merely redirect and dissipate the fumes in the room.

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The best way is to extract the fumes, mask is not a good solution for long term use. A simple low power fan blowing in opposite to you direction can take away the fumes. The best is if you can put a pipe and remove completely the fumes from the room. I guess you're not doing extensive soldering so simply a fan from the computer can do the job.

I used to work with lead free solder with silver but was not satisfied with the results. Once you start working with Balmer Zinn solder you'll understand how smooth and glossy become the soldering, the same feeling like leaded solder but without lead. A fact is that I don't use anymore leaded solder at all (I don't have any in my office).


I would recommend you take the solder with more flux inside otherwise you need to use additional flux for soldering. 1mm thickness for big parts and 0.3mm for SMD is the best diameter of the solder

Lead tin solder is fairly safe for soldering small circuits. You will get a little lead to rub off as you grab it with your hands, so you MUST wash your hands before eating anything.

The fluxes used for soldering are probably a bigger health risk. I just use a small fan that blows air from one side of the work bench to the other. The flux smoke wafts upward, but the fan blows it to one side before it reaches my nose.

You can get fancy and have an actual exhaust fan, but I do not think it is that important.

IF you are planning on doing any grinding/sanding of the solder joints, you MUST use a lead free solder. The fine dust will go everywhere and is a very serious health hazzard. Sometimes I make big waveguide pieces with brass or copper sheet, and solder the joints. That is always with lead free solder (like the type you can legally use on potable copper water piping).

luben111 said:

The best way is to extract the fumes, mask is not a good solution for long term use.

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Why do you say it is not a good solution? I would say a P3 mask (N95) would be pretty effective. At the very least, mask + fan should be better than fan only. Or is it overkill?

Since I don't have a fume-extraction device, I was thinking of doing the soldering outdoors with a fan blowing the fumes away from me.

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biff44 said:

The fluxes used for soldering are probably a bigger health risk. I just use a small fan that blows air from one side of the work bench to the other. The flux smoke wafts upward, but the fan blows it to one side before it reaches my nose.

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I agree with you that flux fumes are probably a bigger concern in general. The question is whether they're really worse in the case of lead-free and whether soldering outdoors and/or with a small fan is enough.

you do not say what you are actually trying to do, but I would suggest that trying to solder an 0603 chip to a circuit card outdoors is pure folly. You need a nice clean area with a microscope.

for now, I am simply soldering simple DIP ICs and discrete components onto protoboards or pre-made PCBs for a robot I am building.

"The last Tommy", first world war veteran died a couple of years ago at the rather premature age of 115 years. He had been working with lead all his life as a plumber.
Don't see the problem my self.
Frank

chuckey said:

"The last Tommy", first world war veteran died a couple of years ago at the rather premature age of 115 years. He had been working with lead all his life as a plumber.
Don't see the problem my self.
Frank

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the fact that it didn't harm a few people doesn't mean it's not harmful in general. I am no MD, but from what I have read lead is dangerous even in small quantities, particularly for kids.

I have been using lead tin solder for perhaps 40 years. I have no problems associated with it. Really, the only way you can ingest the lead is:
1) it rubs off onto your hands, and you eat something without washing your hands
2) you overheat the solder (like with a flame torch), and the lead burns and smokes, and you breath it in.

With normal soldering iron temperatures, it looks like it is mostly the flux particles that are troublesome:
Solder Fume Extraction For Occupational Health | Solder Fume Health Risks

In fact, some sources suggest that you have more health risks from the lead-free solders, because they have higher soldering temperatures than lead-tin solder.

From a multicomp solder data sheet:
"Health and Safety:
Warning:
The following information is for guidance only.
Health Hazards and Precautions: Inhalation of the flux fumes given off during soldering should be avoided. The fumes are irritating to
the throat and respiratory system. Prolonged or repeated exposure to rosin or modified rosin based flux fumes may lead to the
development of respiratory sensitisation and occupational asthma.
Multicomp solder wires must always be used with suitable fume extraction equipment to remove fumes from the breathing zone of
operators and the general work environment.
Solder alloys containing lead give off negligible fume at normal soldering temperatures up to 500°C.
Normal handling of lead alloy wires will not cause lead to be absorbed through the skin. The most likely route of entry is through
ingestion but this will not be significant if a good standard of personal hygiene is maintained. Eating, drinking and smoking should not
be permitted in the working area. Hands should be washed with soap and warm water after handling solder wire."

Don't forget that the lead oxide (in some of the valencies) can dissolve in water and can directly penetrate through your skin, this form of the lead oxide is actually the biggest danger. So it depends a lot on what kind of solder you use, what is the surrounding environment. In dry place without acids vapors in the air you could probably never experienve problems with lead, but in humid environment and if there are some acids in the air the lead can quickly oxidize (thin white layer on the top). Touching oxidized lead with unprotected hands is really hazardous.

i just use 60-40 soldering lead here in the Philippines...
well, I just wear mask, at-least to minimize lead inhalation..

If you live in Philippines where the climat is humid you should worry about lead oxid contaminations - use gloves and wash your hands before eating. Lead is affecting health very slowly, it takes many years before you feel something, but once you start getting health problems they will be last for long time - teeth and bones are mostly affected from lead (everything which contains Calcium, because the the poison form of lead is also 4th valent as Calcium).

@luben,
over here, Brittany, France, climate is humid but not as much as in Philippines. I would tend to go for lead free except that fumes appear to be really bad even though there's no clear information on this.

well, i think i should have also gas mask,

anyway, i just simply use standard desk fan to blow away fumes from my work...