The top brass ferrule on the bellcrank post apparently suffered from a bad solder job (embarassing 'cause I was an electronics tech for many years)
The bottom ferrule joint actually looks like the soldering jobs I used to do on large items until I recovered from doing lots of electronics work. So if I'm telling you a bunch of stuff you already know -- please forgive me.
The key thing to remember when soldering is to get everything clean enough, and hot enough. You know this already, but what I tended to forget for years is that steel needs to be cleaned more vigorously and more recently than just about anything that you'll find in an electronics parts bin, and things like 1/8" diameter rod needs to get a lot more heat than a 30 mil diameter resistor lead. I suspect that you got really nice adhesion to the thin brass (which is doubly easy to solder to because of its makeup and its thinness), and a cold solder joint on the music wire. The "lumpies" in the solder on that lower ferrule are a dead giveaway for a good joint to the thin piece and a cold one on the fat piece.
It looks like you either soldered that with a 30W pencil iron, or one of those crappy "soldering guns" that the unsuspecting buy at Home Depot. Neither of these really do the job. What you want when you solder stuff like this is some well controlled heat source. In a pinch I'll use a propane torch, but what I like even better is really large chuncks of hot copper heated up good and hot. Like Bertha, in the picture. This is an iron that I inherited from my favorite uncle's estate, and which he used (I'm pretty sure) for building Tube Radios of the Gods. It's really a poor fit for soldering surface-mount devices onto boards, but it sure does a nice job on music wire. I plan on using it until I die of old age or electrocution.
If I didn't have Bertha I'd go get one of those nasty enormous plumber's soldering irons and I'd be heating it with a propane torch (and probably burning down my shop).
Whenever I'm soldering something like this that has a big disparity in the thermal masses of the pieces I'll always go back to basics -- make sure that the solder is melting on
both pieces. Generally this means make sure that the solder is melding on the
biggest piece. In addition, unless you're soldering easy things like brass or copper, make sure that you can
see that the solder is really wetting the surface -- just the tiniest bit of finger-grease on music wire, allowed to sit for an hour or so, will make enough surface corrosion that the solder won't stick.
Topic: So here's what happened.... (Read 1965 times)
