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Topic: Switching to lead-free soldering (Read 4507 times) previous topic - next topic


As I am not soldering often, I am still using my remaining roll of solder, which contains lead. I have once tried lead-free solder but it seemed much harder to use. Now I'd like to switch to lead-free for good. So, any advice, tutorial about lead-free soldering (and solder brand choice) would be nice.

Thank you in advance.


My intent is to avoid it if at all possible, but maybe that is not a possibility in Belgium. I've always used only Kester solder, so if I had no other choice, I would look at their lead-free solder first.


For occasional soldering - don't eat the solder. Perhaps set up a small fan to move fumes away from your face and don't worry about it.


I've been using lead free solder for ages now, and haven't had any problems. It is harder to use than leaded solder, but not impossible! I suggest turning your iron temperature to about 350ÂșC, and using one of those flat 'chisel' or 'screwdriver' tips. Even for SMD work, lead free solder is manageable. Do you have trouble wetting the pin/pad or actually getting the solder to melt? The first requires good removal of the oxide layer on the metal (you probably know this but NEVER apply a glob of solder to the iron then move it to the pad, unless in very special cases such as when soldering fine pitch SMDs, where the pads have external flux added anyway, the reason being that all the flux inside your solder burns away when you do this). The latter requires a higher temperature  :)


Lead free solder can be much harder to use, but the exact metallurgical formulation can make a significant difference in how the solder behaves.  In my experience, the more inexpensive tin-copper lead-free alloys can be problematic, so for a two metal alloy tin-silver is usually preferable.  I've also found some of three (like Sn 96.5%, Ag %3.0, Cu %0.5) or four (like Sn 96.35% , Ag 3.0% , Cu 0.5%, Sb 0.15%) metal alloys, have a better performance as a general purpose solder.  However, they are usually almost three times the price of tin-copper.


the big question is WHY??? Unless there is some strong legal reason for you to switch, why bother? the net effect on the environment will be NOTHING! Lead free is harder to use, needs more heat and makes poorer connections. No gain for less performance.


Also joints made with lead free solder are brittle and can cause earlier failure of circuits. And then there is the problem with dendrites, that is tin whiskers forming shorts.


How many grams of solder do you use per year? How does that compare to, eg., one car battery?

There's a lot of sources of lead in the world, I'm not sure hobbyist-level soldering is a big problem.
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Is there really a fumes issue specific to using leaded solder? Lead vaporises at 1750C so surely the fumes are the flux core which you'll get in both leaded and lead-free. I use a fan blowing over my workspace to dissipate fumes.


Oct 30, 2012, 02:48 pm Last Edit: Oct 30, 2012, 04:30 pm by MichaelMeissner Reason: 1
From what I've read, the issue is to clean up all of the commercial electronics to remove the lead from those.  People doing small scale electronic projects were presumably not even on the radar screen for the EU when they enacted the law.  I can imagine a scene from too many B movies, where it is a dark night, you meet a guy with raincoat and he says, he buddy, do you want to score some leaded solder?


the big question is WHY??? Unless there is some strong legal reason for you to switch, why bother? the net effect on the environment will be NOTHING! Lead free is harder to use, needs more heat and makes poorer connections. No gain for less performance.

Because its a potent cumulative poison and lead-free solders are perfectly easy to use - you set your iron for the correct temperature and _use enough flux_.  Nearly all problems with soldering are solved by using a hot enough iron and enough flux.  I've used both leaded solder (years ago) and tin/copper and tin/copper/silver solders more recently and there is no difference if you can solder properly and _use enough flux_.

As for the net effect on the environment go and take a look at the people in India / Asia / Africa recycling precious metals from circuit boards and the fumes they breathe every day(*).  If you want to use lead, you are morally obliged to recycle it yourself I feel.

The only valid worry about lead-free solders is not the points you make, its the long-term reliability issue with tin-whisker formation.

(*) http://en.wikipedia.org/wiki/Electronic_waste_in_Guiyu
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Thank you everyone for those interesting answers.


I've always used 60/40 rosin core lead solder.  Always wash my hands when I'm done soldering.
The fumes isn't the lead but the rosin flux burning off...probably bad for the lungs but ok as long as you have some good ventilation.

I've always wondered if all the problems with the cpu and gpu's from the current generation of game consoles (360 & PS3) are a result of the lead free stuff..

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When I solder, I have a fan that blows the fumes away from my face, and I always wash my hands after. If you do these things when you only occasionally solder, then you should be fine....Nice decision to go lead-free, though! Lead-free solder is usually harder and more dense, so I suggest turning up the soldering temperature  to 350* F. If you don't have a variable temperature soldering station, I suggest buying another iron that is higher in temperature. Good luck with all of your soldering!


Today is my 65th birthday. I've been using lead/tin based solder for most of my life and when a youth use to play with pure mercury which was a lot of fun. I will die of some cause but I suspect that solder and past contact with mercury will not be the reason. Lead free solder is not something will ever play with until, if ever, I run out of my lead based solder and can't find replacements anywhere including E-bay. I'll let others work on saving the planet as I figure the planet as a finite lifetime anyway once the Sun explodes.


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