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  • "Loc-tite" for electrically conductive connections

    From Don Y@21:1/5 to All on Sun Sep 1 22:03:44 2024
    I have many threaded connections that are subject to vibration
    and other mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on
    said connections?

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  • From Bill Sloman@21:1/5 to Don Y on Mon Sep 2 16:38:33 2024
    On 2/09/2024 3:03 pm, Don Y wrote:
    I have many threaded connections that are subject to vibration
    and other mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on
    said connections?

    Loctite is a cyanoacrylate resin that sets when it gets into an oxygen
    free environment.

    It's not viscous enough before it sets to prevent metal-to-metal contact (micro-welding) but once it sets it is rigid enough to prevent the
    screwed connection from unscrewing itself by tiny progressive flexions.

    It should do exactly what you want, if my understanding is correct, and
    that should be easy enough to test (not that I can do it at home).

    --
    Bill Sloman, Sydney

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  • From Jeff Layman@21:1/5 to Don Y on Mon Sep 2 10:31:50 2024
    On 02/09/2024 06:03, Don Y wrote:
    I have many threaded connections that are subject to vibration
    and other mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on
    said connections?

    Any of these useful or adaptable? <https://www.emsdiasum.com/colloidal-compounds-and-conductive-adhesives-4>

    --
    Jeff

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  • From Joe Gwinn@21:1/5 to All on Mon Sep 2 09:41:27 2024
    On Sun, 1 Sep 2024 22:03:44 -0700, Don Y <[email protected]d>
    wrote:

    I have many threaded connections that are subject to vibration
    and other mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on
    said connections?

    In a threaded electrical connection, the current is carried entirely
    in the metal of screw and nut, and mating faces of terminals. These
    surfaces are very rough at the scale of interest, and it's the
    asperities that touch make the electrical (and mechanical) connection.
    The space between asperities can be filled with anything.

    For battery terminals, being lead on lead, I would fill the gap with
    silicon grease and then install battery cable clamp on the post. The
    mating force displaced the grease, which filled the gaps and greatly
    slowed the entrance of sulfuric acid.

    For a terminal, ordinary loctite will do the same.

    Joe Gwinn

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  • From Glen Walpert@21:1/5 to Joe Gwinn on Mon Sep 2 15:18:53 2024
    On Mon, 02 Sep 2024 09:41:27 -0400, Joe Gwinn wrote:

    On Sun, 1 Sep 2024 22:03:44 -0700, Don Y <[email protected]d>
    wrote:

    I have many threaded connections that are subject to vibration and other >>mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on said >>connections?

    In a threaded electrical connection, the current is carried entirely in
    the metal of screw and nut, and mating faces of terminals. These
    surfaces are very rough at the scale of interest, and it's the
    asperities that touch make the electrical (and mechanical) connection.
    The space between asperities can be filled with anything.

    For battery terminals, being lead on lead, I would fill the gap with
    silicon grease and then install battery cable clamp on the post. The
    mating force displaced the grease, which filled the gaps and greatly
    slowed the entrance of sulfuric acid.

    For a terminal, ordinary loctite will do the same.

    Joe Gwinn

    I think that could result in loctite fracture due to differential thermal expansion or shock and vibration, allowing gas ingress and moving some of
    those small asperites over non-conductive loctite. Better would be
    putting a listed conductor termination compound on the terminal mating
    surfaces - for copper or plated copper terminals Thomas&Betts Kopr-Shield
    is good, Burndy makes an equivalent also conforming to MIL-PRF-907E, and
    there are a multitude of compounds for aluminum. Put the loctite only on
    the threads of the screw, being sure that no termination compound gets in
    the nut threads, and of course always use a torque screwdriver to tighten
    to the correct torque. For better reliability in harsh conditions use a belleville washer between screw or bolt and terminal, this combo is
    commonly used in power distribution terminations but is trickier to design
    so that the spring exerts the correct force and operates near its constant force deflection.

    Glen

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  • From john larkin @21:1/5 to All on Mon Sep 2 15:09:49 2024
    On Sun, 1 Sep 2024 22:03:44 -0700, Don Y <[email protected]d>
    wrote:

    I have many threaded connections that are subject to vibration
    and other mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on
    said connections?

    There is electrically conductive Loctite. It costs more than fine
    caviar.

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  • From john larkin @21:1/5 to All on Mon Sep 2 15:05:11 2024
    On Sun, 1 Sep 2024 22:03:44 -0700, Don Y <[email protected]d>
    wrote:

    I have many threaded connections that are subject to vibration
    and other mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on
    said connections?

    I'd expect the regular Loctite to work fine. Try it.

    The real nuisance is scruncing screws down into countersunk anodized
    holes. Undercut flathead screws seem to cut through the anodize and
    make a good connection.

    Star lockwashers dig into metal pretty good too.

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  • From Don Y@21:1/5 to Jeff Layman on Mon Sep 2 19:23:48 2024
    On 9/2/2024 2:31 AM, Jeff Layman wrote:
    On 02/09/2024 06:03, Don Y wrote:
    I have many threaded connections that are subject to vibration
    and other mechanical disturbances.

    Is there something like "Loc-tite" that is suggested for use on
    said connections?

    Any of these useful or adaptable? <https://www.emsdiasum.com/colloidal-compounds-and-conductive-adhesives-4>

    Thanks, I will have to look into them in greater depth.

    If the connector shells were smaller (less massive), I'd just
    solder them in place. But, suspect using a *torch* would
    result in lots of collateral damage...

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  • From Martin Rid@21:1/5 to Don Y on Tue Sep 3 12:28:23 2024
    Don Y <[email protected]d> Wrote in message:r
    I have many threaded connections that are subject to vibrationand other mechanical disturbances.Is there something like "Loc-tite" that is suggested for use onsaid connections?

    Do the crimp on wire sleeves improve vibration resistance?

    Cheers
    --


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