Strange wetting when tinning new tip for the first time

Discussion in 'The Projects Forum' started by AndrejaKo, Sep 17, 2010.

  1. AndrejaKo

    Thread Starter New Member

    Sep 6, 2010
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    Hello! I have new ERSA Multitip 25W soldering iron with 172BD tip. The tip itself has an area of different color at its tip which I assume is used to actually solder.

    My problem is tinning the tip. I've read lots of tutorials and seen lots of videos on YouTube related to tinning the tips. Usually they take hot iron and apply some solder to the tip so that the working end of the tip is covered. After that they clean it with a sponge or the mesh cleaner and it looks nice and shiny from all sides.

    My problem is that only one half of the tip is getting wet. I turned on the iron and waited for one minute (datasheet says that it will reach operating temperature in 60s). I then tried to apply some solder to the diferently colored area of the tip, but it refused to melt. I waited for a couple more minutes thinking that manufacturer exaggerated a bit in the datasheet. After that the solder melted but constantly kept flowing to one side of the tip. At first I thought of gravity and rotated the iron, but then again the soler kept flowing to the same part of the tip. After I cleaned the tip, the covered part looked shiny and the non-covered part was black.

    The shiny part seems to be working properly, but the non-shiny part does not seem to work as efficiently.

    Also the tip itself changed color. Bottom part of the tip is now blue while the top part is yellowish. Iron itself is also changing color and the heating element part which had shiny metallic color is now yellowish. Is this normal result of oxidation?

    I think that I'm doing this wrong and that there is some simple and obvious step which I'm missing.
     
  2. AndrejaKo

    Thread Starter New Member

    Sep 6, 2010
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    Well, after some experimenting, it turns out that I needed much more solder than I expected. It still flows towards one side, but the other is covered now too.
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    You can buy little tins with solid solder paste to wet the tip when putting the iron up. Solder with resin tends to damage cheaper tips.
     
  4. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    If a tip is that hard to tin then I would have taken it back and got another.

    Bil is also right. If this is a cheap iron then it will be hard to keep tinned properly. There are some tools you shouldn't skimp on and soldering irons are one of them. If you plan on doing any sort of PCB soldering I suggest you fork out a few extra dollars and get yourself a good temperature controlled iron and desoldering iron as well if you can stretch the cash. You won't be sorry you did if you plan on doing a fair bit of playing.

    Here in Australia a company called Dick Smith sell a soldering and desoldering pair for about $350. Not the best you can get but for home use it is great.
     
  5. Wendy

    Moderator

    Mar 24, 2008
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    While I agree with what you say it may not be an option. When I was a teen (translate that to dirt poor) I didn't have the luxury of picking and choosing. I would just take my cut rate soldering iron out to the shed and file it with a metal file until the shape was right. It is important to remember not everyone has the finances to the best, or even the better. A $6 soldering will get you up and going (back then it was $1).

    I still made my share of circuit though, in spite of it.
     
  6. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    I made my first circuit (TV ping pong game kit) using an 80W Birko with Bakers fluid and plumbers solder. I was 14 at the time and my only other option at the time was one of those kerosene blow torches heating a huge copper tip on the end of a rod with a wooden handle. Guess which one I chose.

    PS. Game never worked. No idea why:D
     
  7. AndrejaKo

    Thread Starter New Member

    Sep 6, 2010
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    @windoze killa

    I appreciate your advice, but I'm on a really tight budget [I had about 40€ (of which 35€ went for the iron) and temperature controlled soldering irons from manufacturers which have good reputation here are 200€ and up].

    Since you did mention temperature controlled soldering irons, can you tell me how important is their power when working with electronics? I've read that soldering irons with power over 30W have a tendency to cause heat damage in elements they are used on. Would that be true with temperature controlled irons too?


    @Bill_Marsden

    Tip refreshers are a bit rare in my area, but I managed to find a place which sells them. It's the next item on my list.


    I'd like to ask once more about the tip discoloration. Is that normal? I know that tip is going to oxidize at operating temperatures. On the other hand in all photos I managed to find on the Internet, it looks shiny like it was when new.
     
  8. marshallf3

    Well-Known Member

    Jul 26, 2010
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    Yes, the various parts of an iron will discolor right after you start using it.

    As to your tip, it's just heavily oxidized on that one side. Get a can of non-acid flux and alternately plunge the hot iron in it and wipe, it may take many times to get it clean.
     
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  9. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    It is not so much the wattage of an iron that is important but more the temperature. 63/37 solder (eutectic) has a melting point of 273C. 90% of the how to books will tell you the ideal temperature to set your iron to is 300C. This allows for the drop in tip temperature when you place it on the joint. If you don't have a temperature controlled iron then 30W would be about the highest I would go.
     
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  10. AndrejaKo

    Thread Starter New Member

    Sep 6, 2010
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    I found out what needed to be done with the tip. After spending some time hunting down manufacturer's documentation, I managed to find a document which describes best practices for soldering. At one point it said that soldering wire with flux core needs to be taken and wrapped around the tip of the iron. After that, the iron should be plugged in and the solder should melt and the flux should clean the tip.

    It's the first time I heard about something like that, but it does seem to work as advertised. The working area of the tip does look shiny now and solder seems to flow normally over the entire working area of the tip.

    After repeating the process couple of times, I've noticed that a second before the solder actually melts, some sort of substance goes out of it and spreads over the tip. Could it be that flux melts first and cleans the tip which is immediately after that covered by solder?
     
    Last edited: Sep 19, 2010
  11. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    Yep, thats flux. Technicians best friend.
     
  12. marshallf3

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    Jul 26, 2010
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    Mostly, but you're also starting to see some oxides starting to form.
     
  13. prb22786

    Member

    Sep 19, 2010
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    You can use the back of a knife to scrape oxide off your tip, just be very gentle and always scrape away, never in. Just as the other poster mentioned using a file, this is a cheap fix and eventually you'll need another new tip.

    There's also something called "Tip Cleaner" which comes in a little tin and is basically a mixture of acid, solder, and flux in a paste. Nasty smelling stuff but does a good job of cleaning. All very caustic too, don't breathe it.

    Remember, if you're not using a temperature controlled iron, you don't want to leave it on when you're not using it, or it will just oxidize and burn up. Keep it in a heat sink, like the metal holders most irons come with. Any time you put the iron down, tin the tip with solder and clean this off when you pick it up again. Your tip will stay fresh longer.
     
  14. marshallf3

    Well-Known Member

    Jul 26, 2010
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    A bit out of line with the rules but I'm just mentioning context here.

    In the old days radio repairmen would make a box with a diode and switch in it such that when you were't using your iron you could switch it to half power, switch it back and it would be up to heat pretty quickly.
     
  15. windoze killa

    AAC Fanatic!

    Feb 23, 2006
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    I would not use a knife to scrape away the oxide. I also wouldn't use one of those scourer type tip cleaners. Both could do damage to the tip and considering the tips for my iron are over $30 each I prefer to look after them.

    A couple of very simple rules to keep your tip in good order.

    1. If it is a temperature controlled iron don't turn it up too far or for too long. If it isn't then not much you can do about it.

    2. Keep the tip loaded with solder when it isn't being used.

    3. Just prior to putting the tip on the work wipe it clean (away from you) with a dry tissue or paper towel folded.

    4. Load the tip up with sold when you have finished.

    Also note that I said DRY tissue or paper towel. Although a wet one or wet sponge is sometimes recommended it CAN and HAS caused the plating to seperate from the copper tip. It is rare but can happen. It also only seems to be recommended byt tip manufacturers.... maybe they want you to buy more.
     
  16. Wendy

    Moderator

    Mar 24, 2008
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    The cheap tips don't have coatings, which is why I used a file. The iron was done when, like a pencel, there wasn't anything left.
     
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