I am totally new to soldering. But I tried to gather as much information on this topic as possible (e.g the guides by CuriousInventor).

My soldering iron is a simple, unregulated Weller SP 25. For cleaning I used a brass sponge and a standard wet sponge. I always tinned the tip before putting it back in the stand and cleaned it before soldering. I soldered maybe 20 - 30 hours in total.

The tip was a conical, but now one side is flat. (I did not use a file.) I hope you can see the flat tip on the picture properly.

What can damage a tip like that? How can I prevent such damage? I dont want to ruin another tip that fast.

enter image description here

  • \$\begingroup\$ Have you taken a look at electronics.stackexchange.com/questions/4470/… or electronics.stackexchange.com/questions/216/… ? This doesn't look like an exact duplicate to me, but they are at least related. \$\endgroup\$
    – Kellenjb
    Commented Jul 18, 2011 at 20:19
  • \$\begingroup\$ Yes I did. In contrast to the other topics my tip is actually clean and shiny (not on the picture, I was to slow to grab my camera). My problem is, that the tip itself seams to be broken. And I wanted to ask for some advices before I grap a new tip. Dont want to destroy it, too. \$\endgroup\$
    – PetPaulsen
    Commented Jul 18, 2011 at 20:26
  • 1
    \$\begingroup\$ This is typical of the tips in low-end Weller irons, after just a small number of uses. A $10 Chinese iron will do better. \$\endgroup\$
    – Kaz
    Commented Oct 30, 2013 at 1:59
  • \$\begingroup\$ OMG, haha. I didn't notice "Weller" in the question until just now, after posting the above comment. \$\endgroup\$
    – Kaz
    Commented Oct 30, 2013 at 2:00
  • \$\begingroup\$ I hate Weller for how they treat hobbyists with their crap low-end stuff; I could never in good conscience buy a Weller soldering station, even if it doesn't have the issues of a simple, unregulated iron. Good companies make everything excellent, top to bottom. Or if not excellent, then at least no worse than it has to be. \$\endgroup\$
    – Kaz
    Commented Oct 30, 2013 at 2:05

1 Answer 1


This looks to me like a combination of too high heat and crappy tip coating. Unfortunately this is common with unregulated soldering irons. They usually get much hotter than a regulated iron because they always put out the same power, and that power has to be enough to solder against a ground plane or something else that acts like a heat sink. A regulated iron would just crank up the power when needed, but a unregulated iron is stuck with a fixed power, so gets too hot, sometimes way too hot, when just sitting in the holder. I've seen a unregulated 25W soldering iron get hot enough to visibly glow in a dark room.

The excessive heat can not only damage whatever you're soldering, but it speeds up the oxidation reaction that eventually ruins tips. Solder oxidizes fairly quickly, even at normal soldering temperatures. You may have tinned the tip regularly, but I'm sure that didn't last long. Then the tip coating starts to oxidize. Once that's worn off, you're left with copper. Copper is actually eaten away by soldering itself. It migrates into the tin/lead mix, which is one reason solder works so well on copper.

People that buy unregulated irons are shopping on immediate price, so manufacturers make them as cheap as possible. That probably includes the cheapest possible tip coating that looks good out of the box.

So in short, it looks like you got what you paid for.

  • \$\begingroup\$ Ok, thank you! I think I should investigate in a proper regulated soldering iron. When the cheap tip is burning out that fast, the regulated one will definitly pay off. \$\endgroup\$
    – PetPaulsen
    Commented Jul 18, 2011 at 21:47
  • \$\begingroup\$ Some tips are better than others. I don't wish to sound like an advert but the iron-clad Antex tips on the X25/XS range of fixed 25W irons can last for ages - I have an X25 iron with a 2.5mm tip that must be at least 15 years old. \$\endgroup\$
    – Linker3000
    Commented Jul 18, 2011 at 22:06
  • 1
    \$\begingroup\$ I have an old Weller magnastat iron that looks after its tips pretty well (so it's not a Weller problem!). I'd just add to the discussion that tinning tips is important, especially with cheap irons. I've knackered a tip by not tinning it properly on its first use. \$\endgroup\$
    – Al Bennett
    Commented Jul 19, 2011 at 8:53
  • 1
    \$\begingroup\$ I keep a chainsaw blade sharpening file in my desktop toolkit and am regularly re-sharpening and re-shaping my cheap bits on my cheap fixed-temperature soldering iron. Not ideal, but cheaper than buying a new tip every time. \$\endgroup\$
    – Majenko
    Commented Jul 19, 2011 at 11:02
  • 2
    \$\begingroup\$ @PetPaulsen: If you're going to get a regulated iron, take a look at the Weller WES51. The tips last a long time at 600F, which is good enough for small electronics soldering. For large things or desoldering you might have to crank it to 650F or 700F, then turn it back down when done. \$\endgroup\$ Commented Jul 19, 2011 at 12:58

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