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Soldering Experts

Discussion in 'The Tool Shed' started by mickeykelley, Aug 26, 2018.

  1. Aug 26, 2018
    mickeykelley

    mickeykelley Well-Known Member

    Republic of Texas
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    I have a problem I have not been able to figure out. I have soldered 1000's of times for 50 years and have never had this problem. I can't even seem to tin wire. My good old heavy duty 2 temp gun finally bit the dust years ago. So I fell back to an old pencil that I used to tin wires with all the time. But I can't seem to get it to tin. Sometimes I have to hold it to the wire until the plastic insulation starts to melt. I have cleaned the tip, ground it down nice and smooth, replaced it, etc. Finally I went and bought a new gun from HF. Same issue. Then I thought maybe it started when I finally ran out of my solder I had had for umpteen years and replaced it. Was it the wrong stuff, have they changed it? So I went down and got some more making sure it was electronic solder. Same thing. I dare not try to repair a joint on a PCB which I have several waiting to get fixed. Right now trying to solder some crimped connections on tail lights. My old trusty gun was a radio shack but of course they no longer exist.

    Where am I failing?
     
  2. Aug 26, 2018
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Hills of NH
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    Yes, solder has changed - a lot of it is now 5% lead instead of 50%. Check the label. Also check if it is flux-core.

    Also if you are holding the iron "until the insulation melts" I'd suggest you don't have enough wattage to heat the wire fast, before the heat travels along the wire too far. The gun I use is about 260 watts. Also, the connections on the tip must be tight and clean, every time.

    For tough jobs I will use a muriatic acid (tinner's fluid) prep to get the metal extra clean. Then add some paste flux while heating.

    Have you tried different batches of wire, sure the problem is not at that end?

    But I sense you already know most of this...
     
  3. Aug 26, 2018
    heavychevy

    heavychevy Sponsor

    Danielsville georgia
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    If you have a cooking thermometer check your temp when your iron is up to full temperature. If it is below 300 degrees time for a new iron.the new one needs be at least 100 watts. 200 watts or more will work better. It is true that lead is being phased out. Avoid acid core solder it has been known to ruin circuit boards
     
    Last edited: Aug 27, 2018
  4. Aug 28, 2018
    CJ Joe

    CJ Joe Truckhaven Tough!

    Pinon Hills, CA
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    There is a big difference between the big 2 level guns and the pencil types. Having to hold it there is wrong. Rule of thumb is 2-3 seconds for iron contact and solder flow. If not then the temp and therefore the wattage is too low.

    Solders have changed dramatically. In the industry everything is lead-free. You want to know precisely the composition of the solder your are using/buying. I recently needed some large diameter solder as I was making battery cables and had consumed my "old" solder. I was surprised that Home Depot only had silver solder in diameters that plumbers might use. I wonder how many unsuspecting DIY's bought this stuff and failed at sweating copper pipes. Silver solder behaves very different.

    Cleanliness is most important. Flux is very helpful for proper surface wetting.
     
  5. Aug 28, 2018
    chris423

    chris423 Sponsor

    greeneville tn
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    old solder maybe????
     
  6. Aug 28, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Electronic solder is still 60/40 or 63/37 Lead/Tin and has a low melting temperature. You can easily buy it from electronics supplies like Mouser. It comes with a rosin core that acts as a flux. Plumbing solder today is lead free (Tin/Zinc/Copper), which leads to higher melting temperatures. Last project I did with mechanical soldering I used a torch with generic plumbing solder and plumbing paste flux (not silver bearing solder, AFAIK), and it worked fine. Your old solder gun may not be hot enough to melt these new lead-free alloys, especially if the piece is large and sinks a lot of heat.

    Also possible that you are getting the joint hot enough to melt solder but there's not enough flux action to make the wire hold the solder. With old wires, I routinely dip them in electronic paste flux to add several times more flux to the joint than you get from rosin core solder. When soldering new or tinned parts (like circuit boards and components), the flux in the wire is enough, but maybe not with dark old bare copper wire. Rosin Paste Flux #135 in a 2 oz Jar - Brazing Flux - Amazon.com
     
    Last edited: Aug 28, 2018
  7. Aug 28, 2018
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    Actually a lot of electronics these days uses lead free solder, anything certified for sale in the EU (with the exception of avionics or medical equipment) has to be lead free; if it's banned in the EU as far as manufacturers are concerned it's banned everywhere.

    I'm actually a bit surprised that 63/57 or 60/40 is still readily available.

    Restriction of Hazardous Substances Directive - Wikipedia
     
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  8. Aug 28, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Last edited: Aug 28, 2018
  9. Aug 28, 2018
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    As may be but anything made in the US that a manufacture hopes to sell outside of North America will have to use lead free solder. Take a look at the specs for any kind of equipment these days (apart from the exceptions mentioned above), everything is ROHS compliant.
     
  10. Aug 28, 2018
    mickeykelley

    mickeykelley Well-Known Member

    Republic of Texas
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    As I said the problem seemed to start when I ran out of my 'old' solder and the more I think about it, it was a more dull gray color like lead. The new stuff is very very shinny. Probably was a lead and yes it would only take a second or two then flow. I think my issue may be the type of solder I got.
     
    Last edited: Aug 28, 2018
  11. Aug 29, 2018
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
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    Most solder sold today to consumers is pretty much lead free. Zinc iirc. Lead solder is still available if you search for it. The zinc stuff does not bear reheating so you have to nail it the first time, every time. Not as easy to work with either. Solder diameter has everything to do with how well it melts and combines/bonds with the wire strands. Wire gauge makes a difference too. The wire, solder, and soldering iron/torch all need to be matched. For really heavy stuff I actually use a butane torch instead of an iron.
    Do NOT buy the solder meant for plumbing. It is acid core solder and is not good for electrical. Electrical solder is rosin core. Amazes me the electrical gurus here did not mention this (or maybe I missed it).
     
  12. Aug 29, 2018
    heavychevy

    heavychevy Sponsor

    Danielsville georgia
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    Try post 3
     
  13. Aug 29, 2018
    89/01 XJ

    89/01 XJ New Member

    Temple, TX
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    One issue with today's lead free solder in modern electronics is tin whiskers.
    Scientists don't know how or why they form or how and why lead in solder prevents them from forming.
    They only know that lead works.

    These tiny metallic hairs (tin whiskers) can and do cause shorts.

    NASA has done a lot of research on tin whiskers. They were found to be the cause of unintended acceleration on a 2005 Toyota.
    The problem is tin whiskers are so fine they burn up when they cause a short so no evidence remains.

    Nice to know that modern cars with computer controlled everything can suddenly try to kill you.

    Basic Info on Tin Whiskers
    Understanding and mitigating tin whiskers
     
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  14. Aug 29, 2018
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    Yes it's an issue, I've specified to that they need to provide documentation on whisker mitigation. It's not as bad as it was 15 or even 10 years ago though, seems proper heat treatment as well as some plating tricks will keep them in check.

    It's not just tin whiskers that cause equipment issues- the tiles used in computer room raised floors were also causing issues- mostly these were made with galvanized steel backing & the zinc was forming whiskers that would break off & get blown around by the HVAC systems- if they got into the wrong spot things would go "poof". :( We recently took over an old trans atlantic cable station for use as a data center- I made sure the building facilities people checked the floor tiles before I allowed anything to be installed in there.:schooled:

    I hate it when things go "poof". :steamed:

    Now these floors have been in use since the 60's, the whiskers only caused issues starting in the 90's when the traces on circuit boards & component leads shrunk down & got close enough to each other that the whiskers would bridge them.

    This isn't likely to be a problem for anything we do at home but lead free solder is still a big PITA to use.
     
  15. Aug 30, 2018
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Yeah well, I hate them too.

    christine.31176.jpg
     
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