How to remove black spots on soldering iron tip?

Discussion in 'General Electronics Chat' started by Rahulk70, Dec 14, 2017.

  1. Rahulk70

    Thread Starter Member

    Dec 16, 2016
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    Hi guys,

    I've an American Beauty 150W soldering iron with me which I had purchased few years back but only I used it for the first time yesterday.

    I do know about tip tinning. So I heated the iron and applied a 60/40 Pb-Sn and tinned it. But after doing the soldering job for like 2-3 mins even though I used damp sponge it started to turn black and refused to accept solder any more. It started forming beads and wouldn't stick. I couldn't remove it no matter how many times I tried to wipe with the sponge. I had tried using Goot BS-15 acid based ZnCl2 flux. But it just made things worse.

    Finally, after some googling saw a video on Youtube and I tried Rosin flux, paper damp cloth instead of sponge and 60/40 lead as per the video. And this time used a power cord with switch to turn off the iron once it was just hot enough to melt the solder and managed to get it like in the picture.

    So, my questions are:
    1. How can I remove those black spots that still refuse to go away, though I know it wouldn't affect my soldering much? Also I haven't sanded this portion.
    2. I've the following type of leads with me:
    - non flux core 60/40 lead-tin soldering lead (Its thin and I usually use this with my Weller WP35). Used for tinning
    - Weller Radiolot Sn60Pb40 Flux 362 multicore with flux
    - Sn-Pb-Ag soldering lead with silver. After using this things turned nasty with the iron.
    Am I using the right lead for this high powered iron ?

    Thanks. Sorry, for making it long. But I felt I need to explain what process I had followed.
     
  2. AlbertHall

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  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    The tip (plating) is damaged beyond repair and you will not be able to get rid of that black spot.. Which is very minor BTW and shouldn't be of any concern..

    And yes that is very common with non-temperature controlled irons and even temperature controlled ones to quickly reach a "black tip" state..

    At work we typically replace the tips about every 2-3 weeks or so now as the higher temps required by ROHS and the more "aggressive" erosion caused by the solders... Its not uncommon to have them pitted/holes in them,etc.. after only a few weeks..

    I'm not sure what you are using that iron for so its impossible to recommend a proper solder and that iron may be totally the wrong tool for the job..
    I would use an iron like that for soldering heavy gauge wire (8AWG and larger) or similar "heavy duty" work..
    If you are using that for circuit boards/electrical components thats surely the wrong tool.
     
  4. Rahulk70

    Thread Starter Member

    Dec 16, 2016
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    Hi,
    Actually the whole bit became black and that too within a few minutes. In 2-3 minutes I had tinned as soon as it started to melt the lead and almost 2 minutes after soldering immediately the black coating covered the entire tinned tip.

    I had first used acid based flux to remove, I suspect if this made it worse. So, after trying it again with rosin flux only I was able to get the tip like in the second picture. Luckily, now there are only black spots.
     
  5. Rahulk70

    Thread Starter Member

    Dec 16, 2016
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    I'm using it to solder a heavy gauge battery wire to lead acid battery bank. I'll have to order a replacement tip and see. But for time being I've made a power cord with a switch and I turn it off as soon as the solder starts to melt. Also since this is a big one the heat stays for a while.
     
  6. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    Clean to bare metal with 600 grit sandpaper. Immediately tin with 60/40 rosin core.
    Keep tip clean and repeat as necessary.

    Throw acid flux in trash.
     
  7. Rahulk70

    Thread Starter Member

    Dec 16, 2016
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    Hi,
    But when I took the iron yesterday for the first time it had a shiny silvery plating (as per spec it says "paragon Iron clad" tip) on the tip. Wouldn't sanding it remove the coating and expose the copper part of the tip to the lead and eat it away? I had once tried sanding technique on a cheaper 60W iron few years ago, it worked but the tip gradually became kinda blunt.

    Thanks for the suggestion.If nothing works eventually I'll try this.

    What worries me more is this a $100+ device and ruining it is a nightmare for me:eek:. And I should keep away that acid flux and stick with rosin only.
     
  8. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    The tip is already useless. This will get you some life back. Nothing lasts forever.

    Edit: it was a new tip? Return for refund, in that case.
     
  9. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Good.. That is likely a suitable tool then..

    Well.. I'd probably use crimp connectors vs soldering anything but again I don't know all the details..

    PS.. I would never use a file or sandpaper or whatever on a tip.. Its a surefire way to ensure that the tip is destroyed.. Joey just goes with the.. "If its broke then it can't hurt"..
    Looking at the pictures of what you have I would NOT use the sandpaper.. Your tip for the most part is totally fine and sandpaper will just make it worse..
     
  10. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    My tips last for months. Then I use the 600 grit. And they last for months more.
     
  11. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    A little more detail then :)

    Sand paper can be used to remove only the surface oxides if done carefully on certain types of tips (iron core,etc..)..
    Others (copper core,etc..) can be damaged by such a process and once the initial plating is compromised then copper dissolution happens quickly and you get pitting/holes,etc...
     
    GopherT likes this.
  12. Rahulk70

    Thread Starter Member

    Dec 16, 2016
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    Well it was new, but didn't I ruin it? I doubt I'm still eligible for a refund.
     
  13. Rahulk70

    Thread Starter Member

    Dec 16, 2016
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    No, I had sanded only the position below the tip that is tinned as per the second pic. That too only slightly I had sanded just to remove the rosin flux that had flowed and hardened in that small area. I would never touch the tinned area as I'm aware that once the iron coating is lost the copper becomes exposed and it dissolves in lead.
    This had had happened to me once with an old 60W soldering iron. Luckily it was a cheap one. The best one I have is a vintage Weller and she still runs strong!!
     
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