Soldering

[Flyinfool]

Is it possible to ever have "enough" tools?????

[Monty]

FYI Guys,

 

I have been soldering wires in various forms for several decades and have more scars from burns from the standard pencil irons than I care to admit to. But a year or so ago I came across the slickest most friendly soldering iron I have used and I found it at Radio Shack. And the most beautiful feature is that I can pack it in my bike tool bag and solder wires on the side of the road or where ever I am. Here's a good Youtube video of it:

 

 

Hope this helps,

 

Rick

 

Rick, I have one similar to that, and yes it is handy...but...you don't want to use an ungrounded soldering iron on circuit boards. Great for wires though.

[saddlebum]

To prevent static discharge while soldering and even just handling electronic cicuit boards. I always wear an antistatic bracelet. Some boards can be ruined by a static spark, something like what you get when you rub feet along a carpet. I also use a wen gun that has interchangable tips for heavy medium and light duty soldering. the heavy one while solder sheet metal while the light duty is great for circuit boards. I also use a butane one due to its portability.

[OldGazer]

I've read about repairing the TCI, (replacing whatever part it is that swells and could blow up the whole works if it goes bad)

 

And discussion about lifting the ribbon...tracers.....tracks....?????

(not sure of the right terminology....gotta love "old timers")

 

Question is....what is the cause and how do you avoid that from happening?

 

Been "off-line" for a while, so I'm jumping in late. Be that as it may, what you are asking about is "lifting runs" and "lifting pads."

 

This happens when you apply too much heat to a printed circuit board conductor.

 

What happens is the excessive heat causes the run to "de-laminate" because the expoxy has been "over cured". A precursor to delamintation is "measeling" which is typified by the appearance of small white cross-shaped spots in the fiber glass substrate. The "cross" appears because the fiberglass is woven.

 

Soldering "guns" are a big NO-NO when working on electronics. Firstly, the tip temperatures are way to high. Eutectic solder (63/37) melts at 361 degrees F. Any thing above that is wasted. Second, guns are difficult to control and the tips are way to large. Fiinally, and most importantly, the tip of a soldering gun is actually the secondary of a transformer, and as such it can and often does blow sensitive electronic components.

 

With that said, and speaking as a retired Interior Communications Chief and 2M Inspector/Instructor, the only thing a soldering gun is good for is degausing old CRT color TVs.....

[Snaggletooth]

If I had asked my dad to hand me a soldering iron he would have handed me one of these.

 

And that SOB would have been red hot.

 

My how times have changed.

 

Mike

[Condor]

 

With that said, and speaking as a retired Interior Communications Chief and 2M Inspector/Instructor, the only thing a soldering gun is good for is degausing old CRT color TVs.....

 

 

I vaguely remember trying one of those soldering irons with the carbon tip and powered by a couple of AA batteries... I think?? You could solder something and then grab the tip and it was cool to the touch. The one I got didn't work all the well so stowed it away somewhere....

Found it [ame=http://www.amazon.com/Cold-Heat-20128CH-ColdHeat-Soldering/dp/B000RWCRAM]Amazon.com: ColdHeat Classic Soldering Tool: Home Improvement@@AMEPARAM@@http://ecx.images-amazon.com/images/I/21F2TqSuuyL.@@AMEPARAM@@21F2TqSuuyL[/ame]

[Guest tx2sturgis]

Some info I want to pass along:

 

Use a small pencil-tip soldering iron. A temperature controlled iron is best, but a bit expensive for a couple of repairs. So I recommend a 40 watt Weller hobby iron and stand, which cost about $50. The irons that sell for under $25 or so are not good for much more than woodburning.

 

If you get the adjustable 40 watt Weller, set the temp to MAX for soldering, and only use the lower temps when you want the iron to idle between uses. DONT try to solder at low temps, because although it sounds opposite, the components you are soldering around will remain COOLER if you use plenty of heat, since you can get in and get out quickly. If the iron is not hot enough, you have to apply heat for a longer time, and that heat has time to travel to the sensitive components and damage them or even separate the copper traces from the boards.

 

Heat the iron for a few minutes before using it, and if it uses screws or a screw-in tip, re-tighten these (with screwdriver or longnose pliers) after the tip has reached operating temp. A loose tip can allow air into the threads and oxidize, and you loose heat transfer to the tip from the heating element.

 

Melted solder only flows freely on clean shiny copper (or solder- or silver-tinned leads). Use the small gauge rosin-core solder (and formula 63/37) for fine work around components. Avoid lead-free solder! Tin and lead is the best solder combo, but its a bit harder to find. NO acid core solder!

 

Someone mentioned not allowing solder to touch the tip of the soldering iron...sorry, but proper soldering technique involves 'tinning' (applying solder to) the iron tip while its hot, then wiping the hot iron tip on a wet natural sponge, then tinning it again. You want a small coating of melted solder on the tip, so that when it touches the component lead and circuit trace, it will more easily transfer heat, so that as you apply the new solder, it will flow quickly. You do this right BEFORE you solder the connection, if not, the hot solder on the tip will oxidize within a minute or so and you need to tin the tip again.

 

When repairing a cold solder joint, each case is different, but on small and medium sized joints, I heat the solder, then use a small capacity spring loaded mechanical 'solder sucker' with a teflon tip, and with the hot freshly tinned tip, carefully remove the melted solder. Then you will have 360º access to the component lead.

 

Next, take an xacto or hobby knife and carefully scrape the exposed component on all sides, and then scrape the copper pad gently, to get it shiny as well. I dont use chemicals at all.

 

Once the lead and copper pad are shiny, you can resolder the connection. Guaranteed success IF you are careful. After your done, the new solder joint should look shiny and slightly concave, and will NOT have any pitting or dull sections. If it is moved while cooling, it will likely need to be re-cleaned and re-soldered.

 

If you have any old cheap broken radios or anything with a circuit board thats usable as a practice unit, then it wont hurt to practice soldering on these before tackling the actual project.

 

 

Good luck and let us know how it goes.

 

BTW I made a living for 4 years doing board level electronic repairs. I am out of that business now but was a pretty good tech back in the day.

 

 

 

 

 

 

 

 

 

 

 

 

Edited February 20, 2012 by tx2sturgis