Originally Posted by Wingeezer
One thing I found was that the stranded copper brake wires on the trailer were quite black with corrosion even when stripped back quite a bit - I have seen that before and I'm not sure why it happens.
My method to clean them up so they will accept solder is to splay the wires out and try to scrape them to bright copper all around with a craft knife. It still isn't as good as I would prefer but it works. Anyone know if there is a better way? I was wondering if the bare copper could be dipped in anything to better remove the black corrosion?
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. Its 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.
Strip the wires to be cleaned.
Get 2 containers, one for each solution. They can be paper cups, plastic, glass, bowls, whatever you can find.
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.
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.
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.
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.
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