Connect with us

Connecting non-solderable wires

Discussion in 'Project Construction Technologies' started by HANKMARS, May 29, 2020.

Scroll to continue with content
  1. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    I will be using resistance wire which will not accept lead/tin solder. On prototype I would use a loop to loop sort of configuration when one of the wires were solder-able. This would tightly trap the resistance wire but is unsuitable for practical use. I desire to have a positive hold at these connections. How have you seen these connections made up resulting in secure, rugged results?
     
  2. Harald Kapp

    Harald Kapp Moderator Moderator

    10,025
    2,138
    Nov 17, 2011
    HANKMARS and bertus like this.
  3. Bluejets

    Bluejets

    4,056
    847
    Oct 5, 2014
    Crimp link.
     
    HANKMARS and bertus like this.
  4. duke37

    duke37

    5,361
    767
    Jan 9, 2011
    I used to use chromel/alumel thermocouples, there could not be soldered with tin/lead solder so the ends were 'tinned' with silver solder (Easyflow) which would take normal solder very well.
     
    HANKMARS and Harald Kapp like this.
  5. Bluejets

    Bluejets

    4,056
    847
    Oct 5, 2014
    Thermocouples are supposed to use dedicated material type terminations to suit the thermocouple type otherwise the readings will be off.
     
    HANKMARS likes this.
  6. Harald Kapp

    Harald Kapp Moderator Moderator

    10,025
    2,138
    Nov 17, 2011
    Plus a cold junction compensation.
    But theermocouples are not an issue here, as the op asked about resistance wire. On another forum aluminum solder is suggested.
     
    HANKMARS likes this.
  7. duke37

    duke37

    5,361
    767
    Jan 9, 2011
    There will be temperature errors if the junction is not at a uniform temperature. We used compensation cable (copper/constantan?) to extend the couple by several meters and this worked well. The cold junction was at the measuring meter/computer.
    The main problem was making a neat thermocouple junction. This was done with a gas/oxygen flame. I became quite good at this and could make a junction no wider than the two wires side by side so any hole would be small and not have a great effect on the thermal flow.
     
    TCSC47 and HANKMARS like this.
  8. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    I did a short search for screw terminals but decided cost prohibitive. Plus weight and rigidness were a negative. Have not searched cage clamps yet.
     
  9. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    Very nice solution but does not fit this application. Thank you for your response.
     
  10. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    This may very well be the best solution. I assume Easyflow silver solder will have a somewhat higher melting point. Or I can make a silver solution and deposit the silver on the wire by electrolysis. The wire is KANTHAL A-1 FeCrAl alloy. Ferrictic iron-chromium-aluminium alloy. For use up to 2550º F (1400º C). A bit of overkill seeings how I do not wish to exceed 115º F. I will try to post the heat shrinkable connectors that I have purchased.
     
  11. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    I considered crimp links and would fill voids with tin/lead solder but am concerned with wire pulling out. A loop to loop primary connection with a crimp connector filled with solder might keep joint from failing completely but may also result in sporadic conduction.
     
  12. Ylli

    Ylli

    324
    84
    Jun 19, 2018
    A properly sized crimp will make an airtight and secure connection. No 'solder fill' required.
     
    HANKMARS likes this.
  13. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    OK. These are solid wires, not stranded, but still quite possible I imagine.
     
  14. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    I have not tried these yet but am optimistic. WIRE CONNECTOR 1.1.png
     
  15. Ylli

    Ylli

    324
    84
    Jun 19, 2018
    I thought you said the resistance wire was not solderable. These form the connection via soldering.
     
    HANKMARS likes this.
  16. Harald Kapp

    Harald Kapp Moderator Moderator

    10,025
    2,138
    Nov 17, 2011
    Right. A crimp looks different and requires a special crimp tool. Crimping works on stranded wire only. Solid wire is not suitable for crimping, see e.g. here.
     
    HANKMARS likes this.
  17. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    Yes they do. My initial thot was that the mere "snugness" of the connector would be enough to maintain acceptable electrical conductivity. Another reader mentioned silver solder tinning. I will be trying that suggestion soon. The reader mentioned that the silver tinned wire readily accepted tin/lead solder, which does sound correct. And if that all rings true, I will have solved this problem of mine with the help of active readers. Thank you all for your participation. I will let you know the outcome.
     
  18. duke37

    duke37

    5,361
    767
    Jan 9, 2011
    If the resistance wire gets hot, then tin/lead solder would probably fail. Electric elements are often spot welded. You could use Easyflow for the entire connection.
     
    HANKMARS likes this.
  19. HANKMARS

    HANKMARS

    77
    9
    Jul 28, 2019
    Hopefully, maximum temp will be 115º F. Will I be able to use Easyflow with soldering iron? My cheapo adjustable iron adjustment knob implies that it can reach 450º F.
     
  20. Bluejets

    Bluejets

    4,056
    847
    Oct 5, 2014
    I can foresee this ending in a complete mess.
    Just use a crimplink or a ceramic terminal block and be done with it.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads
There are no similar threads yet.
Loading...
Electronics Point Logo
Continue to site
Quote of the day

-