Solder that is…
About a year back, I finally ran out of what had been a one pound spool of 60/40 solder. After debating it for a bit, I decided to refill my supply with lead free solder.
Before I continue…
It is important to understand that I am very skilled at soldering, having had a long and extensive career in the electronics industry. Indeed, in my younger days I instructed people on proper soldering technique. Likewise, I have a decent, temperature controlled, soldering station. Ergo, I’m anything but a novice at soldering.
As noted, I had replaced the 60/40 leaded solder with a lead free spool from a major and, I might add, well respected solder manufacturer (who shall remain nameless). Since that day, I had started to think that my soldering skills had suddenly eroded.
Using the same, proven, techniques and processes that had always resulted in perfect connections with leaded solder, just didn’t work with the lead free stuff. The really upsetting thing to me was that, in order to even have a chance of a decent connection, it was necessary to apply heat longer and/or use a far higher tip temperature.
Neither of those necessities was appealing to me and, as if that wasn’t enough, I found unsoldering to be next to impossible. Circuit boards were being damaged, almost 50% of the time, due to the need for additional time and/or heat on a given connection.
Eventually, I came to the conclusion that my skills had not eroded. This lead free solder was simply crap.
As this spool of lead free solder was finally running out, I also noted that it had become next to impossible to keep a clean/tinned tip on the iron. I was about to consider replacing the tip, but waited.
A few days ago, a new, one pound spool of 60/40 leaded solder arrived. I still have about three feet of the lead free left, but I set it aside to test my theory. One of the first things I did was attempt to tin the seemingly fried tip on my iron…
As Chef Emeril Lagasse would exclaim… BAM!
The once deceased looking tip of my iron took to the lead like the proverbial duck to water.
It tinned right up, something it was all but impossible do with the lead free stuff. After a couple of wipes across the damp sponge and another tinning it once again looked clean and new. I grabbed a project board and made a couple of ‘test connections’. Tip temp set to 750f, a temperature derived from experience… I had no issues at all making a perfect connection and, my 2A2 rule worked as well as it ever had!
2A2 means apply a (clean and tinned) iron to the joint, count to 2 (one Mississippi, two Mississippi), Apply solder, count to 2 again, and remove iron (and don’t bump/jar the joint). All of the connections cooled to a shiny silvery color, not the cold brittle appearance of the lead free stuff. Also do-able once again, easy unsoldering.
As I don’t like to waste anything, I’ll find a use for the remaining couple of feet of lead free solder. However, until I find something that works better than 60/40 leaded or, a better process comes along for using lead free solder that makes for clean connections and doesn’t fry circuit boards, I’ll stick with good ventilation and 60/40 leaded solder.
To be sure, I would genuinely like to stop using leaded solder. It is why I purchased the spool of lead free in the first place.
I am also open to the possibility that a different process may be needed to make use of lead free solder.
Unfortunately, I have yet to find any instructions and/or articles touting the benefits of lead free solder, beyond the environmental/health standpoint.