Soldering tough old bastard wires

[xtian]

I'm reading up on flux, and trying to gather ideas for soldering 60-year-old multi-strand wires in this Sano amp. I've had trouble in the past soldering to old wires; they're so corroded that solder doesn't want to stick. I think the flux pen I have (circuitworks.com Lead Free Flux Dispensing Pen) is probably not strong enough.

Suggestions? Practices?

[Prairie Dawg]

I've got a copper sponge that I use for cleaning off old wire when it's not doing duty as a soldering tip cleaner. Between that and some lacquer thinner you can get them pretty clean and grease free. Just finished work of this kind in an old Vibrolux that had an oddball power transformer with wax saturated cotton insulated wire. What I do is clean as described then rest the bare wire on the soldering iron and heat and drag the solder back and forth until it tins. It's a little messy at times but it takes patience.

[Structo]

When I have difficulty I use MG Chemicals liquid Rosin Flux.

You can buy little flux bottles with needle applicators for pin point accuracy.

You don't want to over do it but it will make the solder flow and stick when it ordinarily won't.

[img:210:456]http://www.electronicplus.com/images/pr ... -100ML.jpg[/img]

[img:500:375]http://farm6.staticflickr.com/5290/5281 ... 3801c4.jpg[/img]

[Phil_S]

I'll go out on limb here and say this particular amp is a "bargain bin" amp, not particularly collectible. I don't mean it isn't a desirable amp, just that it was clearly an economy model (paper covering, not tolex) and there isn't the same market demand as for, let's say a Bassman or Plexi. That means you might have less concern for preservation.

If that's the case, maybe it is simpler just to replace the old wires that are giving you trouble?

[xtian]

I hear you, Phil. Good news is I got the amp for less than dinner for two at my favorite swanky restaurant.

I've been soldering for the last couple of hours (see build thread for new photos). The wires turned out to be in a lot better shape than I feared. No trouble at all.

Thanks for the advice, everyone!