cleaning and soldering tarnished copper wire
cleaning and soldering tarnished copper wire
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woodypup59

Original Poster:

679 posts

175 months

Thursday 20th June 2024
quotequote all
I have a bullet which has pulled off a cable (a thin one - for the wipers earth on an old car).

Stripping the wire back, the copper has black tarnish and despite attempting clean to bright with abrasive, it won't solder.

Is there a decent acid flux I can use, instead of the 'grease' type flux which doesn't seem to work.

I don't want to use crimps as they look terrible.

Mercdriver

3,000 posts

56 months

Thursday 20th June 2024
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Plumbers flux is quite aggressive.

Big Al.

69,329 posts

281 months

Thursday 20th June 2024
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Byker28i

84,270 posts

240 months

Thursday 20th June 2024
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I own a TVR, I'm always cleaning/fixing connections.

TVR electrical problems are usually down to dirty connectors, or the plugs used, however swapping to modern plugs like superseals often exposes a new problem, corroded or dirty wires, stopping soldering connections.

Yet there’s a simple home recipe to cure this.

This process uses two solutions, one is regular table salt and vinegar. Any kind of vinegar will work, from balsamic, to rice, to white vinegars. It’s the acidity and corrosiveness of the salt and vinegar together that you want. The other solution is Sodium Bicarbonate, or baking soda, and water. This is used to neutralize the corrosive properties of the other solution, and to further clean the wires.

Step 1: Strip the wires to be cleaned.

Step 2: Get 2 containers, one for each solution. They can be paper cups, plastic, glass, bowls, whatever you can find.

Step 3: Get 1 tablespoon of raw salt, and put it in one of the containers. Fill up the rest of the container with vinegar, and stir the both together. As a general rule of thumb, put as much salt in the vinegar as will dissolve.

Step 4: Get 1 tablespoon of Sodium Bicarbonate, (baking soda) and add it to the other container. Fill up the rest with water, and stir well. Add more baking soda to make it cloudy. The amount is not important, as long as it is alkaline to cancel the acid of the vinegar solution.

Step 5: Put the stripped end of the wire in the vinegar solution, and stir the solution with the wire. any wire you want cleaned needs to be under the solution. Movement of the wire in the liquid speeds up the process.

Step 6: After 2 minutes or so, the wire will look very shiny and new in the vinegar solution. The acid and salt in the solution is etching away the oxides, exposing the bare metal. Make sure the metal is uniformly shiny. Leave it in longer if it is not perfectly clean throughout.

Step 7: Once the wire is satisfactorily clean, remove the wire from the vinegar, and plunge it into the baking soda solution to neutralize the acid's corrosive properties. If the wire was exposed to the air, without neutralizing the acid first, it would quickly corrode again. The baking soda keeps it clean and shiny. Swish the wire around in the baking soda water for about 10 seconds, and then you are done!! Shiny new wire ready for soldering, and conducting once again!!

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woodypup59

Original Poster:

679 posts

175 months

Thursday 20th June 2024
quotequote all
Thanks Byker for that very comprehensive reply.
It worked a treat !
smile

Mercdriver

3,000 posts

56 months

Thursday 20th June 2024
quotequote all
Ah byker, TVR wiring I remember it well, earth wires especially!

Good tip that filed away for the future, although my car rebuilding days are over.