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How do I go about removing/replacing old wiring in a LOUIS KALFF 1950's Desk Lamp? There is no way the wire will pull through! Pic included to illustrate problem.LOUIS KALFF 1950's Desk Lamp

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  • Will need a close up of the joints. Maybe it comes apart in pieces. They got the wire in somehow when making it, and I bet they did not make it take hours to get the wire in. Do unplug the lamp before trying.
    – crip659
    Mar 17, 2023 at 19:13
  • Include a picture looking into the socket with the bulb removed.
    – JACK
    Mar 17, 2023 at 19:16
  • My very quick search suggests that this is a valuable antique. If it can’t simply be unscrewed and you want to preserve its value, you need to find a specialist. Mar 17, 2023 at 19:24
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    why do you need to change the wiring anyway? It's working, and most retrofits move to LED, which has lower current and voltage anyway; thus wiring that was iffy at mains is better at DC. Also, if you go to DC, you can run the negative on the metal body, so you only have to run 1 small wire instead of 2. You can re-run tricky corners with a vacuum hooked (ok, duct-taped) to one opening, feeding a string into the other, then once the string is sucked out, use that as a fish for the wiring.
    – dandavis
    Mar 17, 2023 at 21:42
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    How far have you stripped it to see what's preventing simple pull-through? There's every chance of a knot under that brass barrel.
    – Tetsujin
    Mar 18, 2023 at 9:49

5 Answers 5

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Decided to go with the old adage "if it ain't broke, don't fix it." Tried pulling with a bit more force and it did start to move but I am not confident I can get another cable through so will leave well alone as the cable looks in quite good condition! Will replace the external cable and use block connector instead of what is fitted. Thanks for the replies, much appreciated, thank you! [replace with block connectorlamp wiring

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    Quite the inside/outside contrast on the external cord - smoke and/or UV took its toll on that.
    – Ecnerwal
    Mar 18, 2023 at 14:59
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Use the old wire to pull the new wire through. You can solder them together, but don't create a big ball or stiff section. Solder it just enough to stay bonded together.

There is a special lube for pulling wire. Go to your local ACE or HOME Depo and ask the people in the electrical department. Put it in from the top and give it time to work its way down the first bend. Then use a syringe to reach into the base connection. The lube is made for this. DO NOT USE SOAP. The chemicals in soaps can dissolve the wire insulation over time and cause a short.

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    The OP has already stated that there's no way the wire will pull through.
    – JACK
    Mar 17, 2023 at 20:33
  • that is what I would do
    – Traveler
    Mar 17, 2023 at 20:55
  • He might have to pull the wire past the sharp corners and work through the ends of the main rod to take advantage of the complementary angles.
    – gnicko
    Mar 18, 2023 at 14:34
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I used to work in a light manufacturing factory when I was at Uni, before everything went to China.

Normally all parts are made separately and screwed together. Metal to metal joints would have loctite, so will require a bit more effort to undo. So it should come apart.

Its possible they have been glued. But if its not working, then what have you got to lose.

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    If it is a valuable antique as one comment suggested, then it will probably be more valuable as non working than broken. The normal household lamps probably won't care as much.
    – crip659
    Mar 17, 2023 at 19:31
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It may be easier to use the existing wire to pull a sturdy string through, e.g. mason's line. Preferably something fairly slippery. Then use the string to pull the new wire through.

Part of the challenge is avoiding a big lump or edges that will get caught. You can strip back the wiring a bit and twist two conductors together to form a small eye. A bit of solder or epoxy will keep it intact. Thread the string through the eye and tie a reliable knot, e.g. a bowline. Or avoid pulling a knot through altogether by simply looping the string through and using enough length to pull the doubled string through.

Reverse the process to install the new wire. Use a sharp knife to relieve any edges on the insulation and jacket that might catch. Keep feeding the wire in while the string serves to guide it through.

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  • The OP has already stated that there's no way the wire will pull through.
    – JACK
    Mar 17, 2023 at 20:34
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    @JACK just because an OP says something, doesn't mean it's true. OP preconditions only have force on puzzling.stackexchange.com Mar 17, 2023 at 20:53
  • @Harper-ReinstateMonica True in a lot of cases but here the OP's probably tried to pull the wire through and couldn't and didn't want a bunch of answers saying to use the wire as a pull string.
    – JACK
    Mar 17, 2023 at 21:02
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    There are at least two sharp corners to pull against, plus maybe OP does not know there might be wire knots inside to prevent pulling.
    – crip659
    Mar 17, 2023 at 21:21
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Update on progress with lamp! I managed with some lubrication, string and perseverance to replace the 2core wire inside the lamp frame. I would now like to change the external wire to three core and earth the metal frame. Any suggestions on how to do this? Ideally earthed inside out of sight. I could drill a small hole in base and use a small brass screw but I would like to keep lamp as original looking as possible so am reluctant to do this. 3core live and neutral wires would be wired with plastic connector to 2core internal wire inside base leaving earth to be attached somewhere/somehow? Thank you for replies, much appreciated!

enter image description here

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  • This should either be edited back into your original question, or posted as a new question; it isn't really an Answer, and folks can't post Answers in reply if it isn't a Question.
    – keshlam
    May 22, 2023 at 16:32
  • It would be nice if you included some more detail about how you accomplished it. Lube obvioiusly, but how did you get string around the bends without dissassembling the lamp? Your new question should be posted as a new question.
    – jay613
    May 22, 2023 at 17:18

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