After a few hours practicing desoldering on old computer boards with a cheap RadioShack 40W (~800F) iron, I noticed the very tip started disintegrating. My preparations were instruction manual-perfect; before melting each contact I applied flux to prevent oxidation and improve wetting, and after, to clean oxidation and residue from the tip frequently, I vigorously brushed it with steel wool, which I now figure might be damaging given how abrasive it is and how thin the copper core's protective coating is. Or--without verifying with chemical calculations--I figured the strength of the flux's acid dissolved both the coating and copper, or only the copper after wool exposed it. Furthermore, from what little I've read, 600-700F of 15-25W irons are sufficient for most solder alloys. So is the flux's acid too strong when liquified; the steel wool too abrasive; the soldering iron poor quality or too hot; or a combination?

Pictures will be uploaded soon.

Thanks

 

My radioshack iron fell apart too. Once I upgraded to a real soldering station I haven't had the problem at all and I still am not very careful with it. I don't know if you should read too much into it, I think it's pretty typical of a cheap iron.

 

Solder will dissolve a plain copper tip. That's likely what happened to you. A good tip will have cladding that prevents this. But you must be careful not a abrade this cladding such as with steel wool. A damp sponge is best for cleaning the tip.

Edit: I know at one time they sold solder with a small amount of copper already dissolved into the solder to minimize this type of tip erosion.

 

Every permanent tip will become destroyed by steel wool.

If it is totally blackened, carefully use a sandpaper.
Make an envelope, and pull the tip through it, only applying light pressure.
Repeat until no more blackening appears on the paper.

The tip will not become damaged if you do it right.

A plain copper tip will always dissolve sooner or later.
They are only designed for hobby use, means a few hours now and then.

For desoldering you always should use a 50W iron, and a broad tip.
If the components don't desolder, apply a little fresh solder wire. This is a good trick. Flux is only meant for new soldering work not so much for desoldering.

 

When the tips go bad, I always take them off and use a bench grinder to put a new conical point on. Tin it immediately, and you're good to go.

 

Copper is so soft, you can cut off the top with pliers.
Not to say, you would not want to cut it at 90 degree, but at 45 degree.

I don't use copper tips anymore for a while, but back then, I have renewed them this way.

 

photos relating to equipment in original post:

http://s1310.beta.photobucket.com/u...deringirontip_zps1912a78d.jpg.html?sort=3&o=2

http://s1310.beta.photobucket.com/u...gfluxtinfront_zpsff0b146b.jpg.html?sort=3&o=1

http://s1310.beta.photobucket.com/user/Steelven/media/solderingfluxtinback_zpsf8c02927.jpg.html?sort=3&o=0

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To eliminate some of the variables and malpractices, I resumed soldering with a Weller--unknown wattage--while diligently cleaning it with a only a damp cloth; tinning it; and avoiding refluxing before desoldering. In spite of all these precautions, its tip suffered the same fate. The advice which I neglected, however, was to unplug it throughout the couple hours' practice.

 

#4 or #6 gauge solid copper wire (used for grounding electrical meters and pipes) cut to approx length of new tip, sharpen to a point with a bastard file and pop it in. When it gets heated up to working temp, just rub it on the file a few times to knock off any oxidation/carbon and then take some plumbers lead free tin RoHS crap solder with a generous amount of flux on the solder wire and just wet the heck out of the tip. Yeah sounds crazy but it works... it actually kinda baffles me that if you use the "good" solder it won't wet the tip for love nor money. Tap the iron on something to knock the excess blob off, wipe with a damp cloth and you will have a nice clean (for a few minutes anyway) razor sharp tip that will instantly melt solder as soon as it touches it, or you can use it for desoldering as a prying device to straighten though hole leads that have been bent down. Best of all you can buy new tips by the foot... I think it costs me around a quarter a tip for my $4 Harbor Freight soldering iron, which is on tip #2 after about three months of having run continuously for most of that time.

I'm hell on irons.

 

photos relating to equipment in original post:

http://s1310.beta.photobucket.com/u...deringirontip_zps1912a78d.jpg.html?sort=3&o=2

http://s1310.beta.photobucket.com/u...gfluxtinfront_zpsff0b146b.jpg.html?sort=3&o=1

http://s1310.beta.photobucket.com/user/Steelven/media/solderingfluxtinback_zpsf8c02927.jpg.html?sort=3&o=0

-------------------------------------------------------------------------

To eliminate some of the variables and malpractices, I resumed soldering with a Weller--unknown wattage--while diligently cleaning it with a only a damp cloth; tinning it; and avoiding refluxing before desoldering. In spite of all these precautions, its tip suffered the same fate. The advice which I neglected, however, was to unplug it throughout the couple hours' practice.

Why would you use Oatey?

That's flux for heavy duty soldering, brazing, sweating, etc.

All you need is rosin core.

 

I have had this problem a lot in the past, it was due to penetrating the protective outer layer of the tip as Mr Crutschow mentioned. I have a decent soldering iron & tip now which has slowly been corroding half way down the shaft for about two years
I clean the tip with one of these scouring pads for dishes:

Edit: I know at one time they sold solder with a small amount of copper already dissolved into the solder to minimize this type of tip erosion.

It is still made, it was the only stuff I could get for a while when I started electronics and I know it is still availiable, I used to buy it from maplin I would think rapid also stock it

 

I have had this problem a lot in the past, it was due to penetrating the protective outer layer of the tip as Mr Crutschow mentioned. I have a decent soldering iron & tip now which has slowly been corroding half way down the shaft for about two years
I clean the tip with one of these scouring pads for dishes:

It is still made, it was the only stuff I could get for a while when I started electronics and I know it is still availiable, I used to buy it from maplin I would think rapid also stock it

That's similar to what I use. This one uses curly, brass shavings, to clean the tips, it was only around $5.00.

No more sponges.

 

A wet sponge will cause heat shock to the tip, but the water will also oxidize the tip, so the brass shavings are much better.

Stellven: The combination of aggresive brazing flux and steel wool is what killed your tip. The steel wool is so hard that it scraped off parts of the protective coat, and then the flux finished the job under the coating. Next time use stuff that is meant for fine electronics, not for sheet metal

 

At the aerospace company where I worked, all circuits were assembled by NASA certified soldering technicians and they all used damp sponges to clean their soldering tips. That's why I recommended using a sponge. It doesn't significantly erode or abrade the tips and apparently the heat shock is not a problem.

 

The tip of my UNGAR soldering station model UTC-300 became unusable about two months ago and a google search revealed that it is no longer in production. The higher temperature required by lead-free solder makes it more difficult to keep the tip in good condition.

Timescope.

 

I clean the tip with one of these scouring pads for dishes:

It is still made, it was the only stuff I could get for a while when I started electronics and I know it is still availiable, I used to buy it from maplin I would think rapid also stock it

I call that a stainless steel Dobie Pad. You can get them from Grainger.

 

I resumed soldering with a Weller--unknown wattage....

It's a 25W.