I had been considering including soldering into my Intro to Computer Science curriculum and providing students with PiDroid Alphas to build. Until I’ve mastered it enough that I can confidently provide scaffolding to my students, I’m instead leaning towards the pre-assembled GoPiGo. I will forge ahead in my own studies and look to develop a more robust offering next year.
In the meanwhile, here are the the lessons I learned:
Mistake 1: Picked the wrong instructional videos
I watched a few YouTube videos on soldering and felt pretty confident, enough that I could give it a try at least. I chose poorly. The videos skipped key concepts and some modeled practices that were just plain harmful (i.e. driving a soldering iron through cardboard to clean off excess solder).
What I should have done was drop a line to an industry expert to make some recommendations. When I smartened up and did just that, here are the incredible videos that were recommended: 1) Soldering, 2) De-soldering, and 3) Tinning wires
Mistake 2: Solder was too thick
My incredibly helpful maintenance department loaned me some solder they use for their electrical projects. It was 1.6mm thick, just terrible for this small of a job. I needed less than half that diameter. In the future, I’m going with this 0.381mm solder. Again, thanks to William from Mikronauts for straightening me out.
Mistake 3: Did not get the pins hot enough
I was having a really hard time getting the solder to stick to the metal I was trying to coat. There a few reasons for this, but one of the reasons was I did not adequately heat the material. In the video linked above, it explains a tiny dab of solder should be added between the metal and the soldering iron. That liquid will help conduct the heat and prepare your surface.
Mistake 4: Did not recognize oxidation
Because I failed to dab a bit of solder on between the soldering iron and the metal I was trying to coat, not only did it take me longer to heat, but the rosin that’s in the center of the solder couldn’t transfer to the metal. You need flux to solder. So I was heating the pin without the protection of flux to keep it from oxidizing. The metal lost its luster and subsequently repelled the solder. I made a very hostile environment for the job.
Mistake 5: Resorted to dripping solder on iron
Having such a hard time due to the last two mistakes, I started scrambling for alternate methods. I resorted to the terrible practice of adding gobs of solder to the iron and then trying to smear it on from there to the metal. This does not work well and the results show it. Once things weren’t working the way I expected, I should have stopped and evaluated what was going wrong before trying to compensate with sloppy methods.
Mistake 6: Failed to clean the soldering iron
Like a witless lemming, I found myself driving my soldering iron through cardboard to “clean” it. But I saw it on YouTube! Well, this is a miserable practice as it starts to oxidize the soldering tip. It should be cleaned properly using a sponge, cleaner, and then given a little solder to tin the tip and protect it from oxidizing.
I hope these lessons learned help you avoid the same mistakes.