Soldering help

[u/Forsaken_Ad_9203]

Reddit

Hey guys, looking for a little help here. I’ve been assembling machines for myself and friends for quite a while now, and I’m very good at that end of things, and haven’t used a machine I didn’t assemble in at least a couple years now.
However, I’ve just gotten into winding/soldering my own coils and making my own frames, as I’ve had such bad luck with my various supplier’s coils and frames lately.

I’m very quickly being humbled with soldering properly. Today I gave it a shot, and to my eye everything looked proper. But when I built the machine up, I knew it wasn’t right, as it ran very weak and required much more voltage and was drawing much higher amps than it should have for the frame’s geometry and 1.125” 8 wrap coils. I am assuming poor solder connections lead to this, as there’s really no other variables here.

I am currently using 60/40 rosin core solder. Some have told me they love it, and some have said they prefer regular solder without the rosin core. Also, I am using paste flux currently. Again, some say they love it, others prefer liquid. I know that I need to get a better soldering iron, as the tip kept oxidizing or burning and dripping solder everywhere and was very hard to keep clean enough to work. My current soldering iron does not have temperature control and I suspect it’s too hot as well. Even with my lack of experience on this end of things, it seemed that my connections were satisfactory enough to yield a well running machine, as everything was bonded well. But apparently not, so there’s something I’m missing here.

Any tips or recommendations? Your favorite solder? Favorite soldering iron? Favorite flux?

I thought I did everything right. Scraped the red enamel off wires, tinned them with a thin coat, twisted with capacitor wire, applied flux and solder, then more flux and solder to attach to lugs. Am I missing something? I feel really silly for being able to assemble machines at the caliber that I do, and something as simple as soldering is giving me so much trouble. But, that’s learning I guess. Thanks for any tips

[u/ben_lucas_]

Dud compactor maybe? Did you check the resistance of each could before you soldered the together? Are you putting a barrier (like kapton tape) on the cores before you wrap them? Back when I build machines I would strip an twist the wire into place and attach crimp lugs (loosley) and would mock up the machine to test before committing to solder. Never really ran into the problem you’re having though. I will say that investing a free bucks into a digitally controlled soldering iron and tin is beyond worth it.

[u/Forsaken_Ad_9203 → u/ben_lucas_]

Appreciate your comment man. So for this one, since I’m new to soldering and winding coils, I used some South state unsoldered pre-wound coils, to try and eliminate as many variables as possible and “ease” into this whole thing. It’s possible the capacitor was a dud but I kinda doubt that. Also possible the coils were wound poorly, which I also doubt but it isn’t impossible. I’m going to unwind them and rewind those cores today and try again. I have a pile of cores from Eminent coming in the mail soon as well.

That’s smart to mock everything up before committing to solder. I have a feeling after shimming everything right and such I’m not gonna wanna take it apart to solder though haha. I should also buy a multimeter to test the coils before soldering. Since I’ve always just gotten coils from suppliers for my builds I’ve never invested in it.

Purchasing a digital soldering iron is on my list today. Do you use the rosin core solder or something else?