Lead solder for the win!

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My 2003 Ford Focus had the common issue of having the jacket on the ignition coil wires disintegrate causing performance issues. I soldered a new ignition coil pigtail on it years ago. I used the regular Home Depot lead-free electrical solder I had on hand and have been using for ages. The car ran much, much better, but it wasn't what I'd call perfection. Considering what I bought the car for and the fact that it passed emissions with flying colors, I was ok with it.

As of late, the car had developed a slight miss at part throttle. It was never all the way right, but it seemed to become a bit more pronounced.

I knew it was ignition system related (you know how when you own a car for so long, you just "know" your car? That.). I just had to figure out where the weak link was.

I figured I'd use this as an opportunity to replace (and upgrade) the ignition coil, wires and spark plugs for something better than what was on there. It ran much better, but still had that part throttle miss (albeit a lot less). Something in my gut said to buy some leaded solder and clip the old soldering job off and do it over with the leaded solder.

The result is the car runs better than it ever has during the time I've owned it. That slight miss is gone, it accelerates a lot smoother, I picked up additional mpg (it was just one mpg, but I'll take it) and little stuff that existed the entire time I've had the car such the engine having a bit of a surge at idle with the A/C on are now gone. The car starts up like a champ on cold starts and hot starts are nearly instantaneous.

I don't think I'll ever go back to using lead-free solder. Is there a notable brand of lead solder out there? I ordered the highest rated lead solder off Amazon. I wasn't necessarily looking for a specific brand. Just something with good feedback. After this roll of solder runs out, if there is a notable brand out there, I think it's worth the $$$ based on this experience and I'll be using it going forward.

Figured I'd share this information for anyone that cares or has electrical stuff they can't quite figure out.
 
Rosin core, definitely, although you can get by with brush-on flux. Just not worth the effort though.

Kester 63/37, although I have some 60/40 that I've been using for years. Radioshack, but rumor has it that it's just rebranded Kester.
 
There is a place for lead free solder, and it's NOT electrical connections. However, it is important to point out that the solder does not make the electrical connection, it is the physical joining of the wires that makes a connection good , OR bad.
Solder just holds everything in place, free from movement, and protected from the elements.
 
I use Kester 63/37, rosin or no-clean flux type. Which to use depends on the application. Sometimes it is impractical to clean rosin flux residue off after soldering and/or you don't want that acidic gooey mess left behind in a humid environment.

Adding a little flux can help make better joints, especially on less than perfect metal, or very tiny soldering jobs, with less solder so less expense in the long run. I mean rosin/alcohol based flux not plumbers acid flux.
 
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There is a place for lead free solder, and it's NOT electrical connections. However, it is important to point out that the solder does not make the electrical connection, it is the physical joining of the wires that makes a connection good , OR bad.
Solder just holds everything in place, free from movement, and protected from the elements.
+1
 
There is a place for lead free solder, and it's NOT electrical connections. However, it is important to point out that the solder does not make the electrical connection, it is the physical joining of the wires that makes a connection good , OR bad.
Solder just holds everything in place, free from movement, and protected from the elements.
Not sure I agree with that. A great deal of electronics runs just fine with leadfree solder; a thin layer exists between copper pads and pins on circuit boards. High current connections, yes, direct copper to copper (welding or crimping) is best for lowest resistance.
 
In fact RoHS forbids lead solder since 05 IIRC, initially there were a few issues and people are still complaining about poor joint quality. I still like a rosin core lead/tin solder for electrics. The Kester 63/37 is highly regarded.
 
There is a place for lead free solder, and it's NOT electrical connections. However, it is important to point out that the solder does not make the electrical connection, it is the physical joining of the wires that makes a connection good , OR bad.
Solder just holds everything in place, free from movement, and protected from the elements.

Have you ever soldered a resistor, capacitor, or other device to a pc board? Just one example of the fallacy of your statement. Not disputing the soundness of your point when possible, but in many cases it doesn't work that way. And many devices are designed NOT to be joined as such.
 
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Yep, leadfree is a pain, but it's pretty routine now. However AFAIK it's not required stateside. And even then, it appears that there are loopholes: lead was always allowed in certain cases, such as if the technology required it (some BGA's qualified, as there was no good leadfree option, and I believe aerospace still has a cutout since reliability outweighed everything else), and if the item in question will be returned to stateside, it can be sold even containing lead--since it will return to the US for recycling (company to company sales, not applying to consumer sales).

I look every few years into it, and it's always a bit more murky than I care for. I just review it for my immediate needs though, and then proceed to forget the details...
 
Have you ever soldered a resistor, capacitor, or other device to a pc board? Just one example of the fallacy of your statement. Not disputing the soundness of your point when possible, but in many cases it doesn't work that way. And many devices are designed NOT to be joined as such.
Actually I built an entire Zenith 27" CRT TV many years ago, One component at a time! So, yes. Fortunately, those kinds of solder joints are intended to be done just that way.
Part of the class that I took stressed the stability and suitability of the joint before it is soldered.
There was no RoHS back then, and in fact lead free solder is most likely banned by them for worker safety reasons, not because it makes a better joint.
I'll admit that silver is a better conductor of electricity than lead is, but that's only part of the story. The melting point of silver is so high that any component, in fact any copper itself will be burnt long before it melts. Therefore a bunch of low melt TIN and Antimony is added to the mix to lower the melting point.
Silver solder, commonly available at Lowe's or HD is intended for plumbing use, where such extra heat is not as much of a factor.
 
There are many non lead solder alloys. My personal favorite is 96.5sn and 3.5% Ag Melts at 221F so reasonable. Can be expensive. I retrieved a full 1 pound roll from the trash because it "expired" Been using it for 20 years now, seems to work fine.

Rod
 
When I recapped a Lexus ECU and did a car audio installed, I used Kester 60/40 Pb/Sn rosin-core solder. Pb-free solder is more brittle and doesn’t flow well(which explains the Nvidia GPU failures in MacBooks and Xbox 360s - the BGAs will electrically isolate from the main board despite being physically attached).

the old-time electronics shop closed down, so it’s one more thing to get off Amazon. ☹️
 
Have you ever soldered a resistor, capacitor, or other device to a pc board? Just one example of the fallacy of your statement. Not disputing the soundness of your point when possible, but in many cases it doesn't work that way. And many devices are designed NOT to be joined as such.
watch a wave solder machine at work, bath of solder at work.
 
I miss radio shack. They had very consistent solder and soldering tools. Now it’s Amazon, and you cant hold it in your hands before buying.
 
Lead free solder like is used in copper pipe joints should be applied with a bit hotter temp than typically found with a propane torch. That why MAPP gas torches were developed. You can still use regular propane torch with lead free, if you know what you are doing. MAPP is easier if you know what you are doing. Much easier if you don't know what you are doing
 
Like the OP I replaced a relay in a Ford CCRM in 2008 and soldered the new relay to the circuit board with lead solder. This was on a 2002 Ford so my repair has lasted longer than the factory solder joint and relay did and it's still working. Best of all I fixed it with about a $3. relay and maybe 30 minutes of my time instead of paying over $200 for a new CCRM.
 
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