Soldering jacks and switches

[TrentC]

Hey guys. I have gotten down soldering on perfboard and pcb's, but I feel like soldering the jacks and switches are very difficult. I think the Red Llama I just built only has a matter of time before a joint on the switch breaks. Do you guys have any tips for how to get a good solder joint on these?

[Mark Hammer]

Sure: Prep the lug.

But how, you ask?  I generally take my X-acto blade and scrape the surface of the lug so that the *real* conductor underneath the plating is exposed.  Even if it is not a plated lug, or if the plating if the "right" material, it may be a jack or switch that has been sitting around unused for too long and there is some oxidation on the outside. which needs to be removed to more readily accept solder.  If you have some liquid flux, dab a bit on the lug where you have scraped it, and tin the area with solder.  It is usually helpful to have thin gauge solder, such that it melts easily and quickly with moderate heat.

Also, prep the wire.  You can do that by dabbing on a bit of flux and tinning it as well.  Both the wire, and the thing you are soldering it to should NOT be dull in appearance or have anything that inhibits a quick solder joint.

Relying on copious amounts of heat to melt thick solder to an unhospitable lug is a recipe for failure.

[petemoore]

  Yupp trick is to not overheat the internal mechanics.
  High iron heat is nice. Pretinned everything is also [let the switch cool after each heat application].
  So you have your de-insulated wire pretinned, next to the pretinned lug, heating the wire first, then soldering it to the lug makes for a shorter time applying heat to the switch. The trick is to get the lug to solder melting temperature before the heat dissipated into, and bakes the switch. Having the right amount of solder already on the tinned components allows the actual soldering-to task simpler and quicker, it takes time to heat cold solder, so a barely tinned lug and small heated blob on the wire end allows a good joint to be made in >2 seconds of lug heating.

[Processaurus]

A lot of switchcraft enclosed jacks I've been chipping away at for years, all have this gray oxidation on some of the contacts, and I have to sand both sides with some fine grit sandpaper to get it shiny and solder to stick to it, otherwise it just kind of balls up on it in an ugly way.  The combination of sandpaper to remove oxidation, and liquid flux is the way to get cooperation from the filthiest metals.  Usually just one of those is enough.  A stubbier soldering tip can help too with transferring more heat for the weld.

Another box I have of jacks are fine, probably because they came with some silica gel packets to soak up humidity, probably a good idea for the parts drawer if you're storing electronic parts in humid country.

Relying on copious amounts of heat to melt thick solder to an unhospitable lug is a recipe for failure.

Absolutely, if it doesn't happen in 5 seconds, the surface needs some prepping.

[differo]

Specially the cheat taiwan-made jacks can be destroyed with too much heat (happened not once to me ), pre-tinning makes it so much easier.

[TrentC]

Thanks guys. These tips are going to make my next build a lot easier!