[geom_tol]

Have you guys experinced problems soldering wires to sheetmetal parts that have a chrome like plating, like the phone jacks that radio shack has?

When I try to solder wires to them the solder just runs around and doesn't want to stick. I heat the stuff up so the plastic parts it's connected to almost melts etc... And I always tin the wires.

Eventually I get the stuff to stick but it's a pain. Sometimes I rough the surface up and that tends to help a little.

On the other hand I never have any problems soldering components and wires to circuit boards.

Is there a simple answer to my problem? Am I doing something wrong?

 

[tangent]

The reason RCA jacks are a problem is that there's so much metal there -- they act as large heat sinks, which you have to heat completely up to soldering temperature before the first solder will flow and stick. Perhaps a hotter iron would help, not because you need the higher temperature in and of itself, but because you want to heat the piece up as quickly as possible. 300 degrees C is about all you'll need, even for fairly heavy jacks.

When you do this work, you must be clamping the jack in something, like a set of helping hands or a Panavise. The less metal-to-metal contact you have, the less metal you'll have to heat up. You might even use some tough cloth, like denim, around the jack to insulate it. Then you'll only have to heat the jack, not the clamp as well.

EDIT: I just remembered one minor detail: with standard RCA jacks you have to put them in the panel before soldering the wires. You might either add the solder ahead of time, and then re-heat it and put the wire in. Or, try to solder it with the wire sticking through the nut and panel, with the jack not in place yet. This would be helpful if you're using a metal case -- again, the less metal you have to heat up, the faster you can get it up to soldering temperature.

 

[geom_tol]

I understand. I will crank my iron to the hottest setting next time and see if it works better. Thanks!

 

[tangent]

One more tip: the rule of soldering is to heat the item being soldered, and let that melt the solder. (As opposed to melting the solder on the iron and basically wiping it on the piece.) More than for resistors and such, it's critical in this case. Heat the piece until it will melt the solder itself -- don't touch the solder to the iron tip at all. This will ensure that you're getting the piece hot enough. It also ensures that you don't start burning your rosin until the solder starts melting. You can get away with bending the rules a little bit with resistors and other small components, but with big stuff like this, you gotta follow the rules of soldering.

 

[Bobes]

So what's the difference in solder? I read that rosin core is not the best for audiophile apps, why? What solder is recommended for audio apps? I'm interested because I want to start building my own cables and work up to building an amp. I want the best for my connections.
Bobes