Resistance welding stranded copper wire

By gangel99 (*)

Date 01-23-2004 02:00

Maybe a dumb question but what's wrong with solder?

By Tim Buyle (**)

Date 01-23-2004 08:11

We did some tests with this problem in the past.
The only solution that was satisfactory is the following :

- shrink/clamp a thin walled Cu tube on the stranded wire
- spot welding of the Cu tube to the Cu contact
- equipment from "Unitek" : www.unitekeapro.com

In my opinion the best solution is brazing with a very fine oxygen/hydrogen torch and a Cd-free silver consumable.
This equipment generates a hydrogen flame by dissociating distilled water into hydrogen and oxygen. The "flame" has an aperture between 0.003" and 0.062" : it is very very small !!!
Look at www.azhydrogen.com/works_mainframe.html
I love this one ! The equipment is not expensive (compared to a spot welder) and gives better results !

By longhorn Date 01-23-2004 15:08

Our vendor has been wrapping a copper tube around the wire, but we are getting upredictable results with the strength of the weld. It seems to me that the gauge of the wire and thickness of the contact might make it difficult to get a good weld. The electrodes of the spotter are hitting the top of the copper tube and the back of the contact. There are 4 material boundaries in between the electrodes, and I am concerned that the copper tube is not getting enough juice to make a connection that can stand up to a little pushing and pulling in the field. I realize that our vendor's welding process, machinery, and general willingness to do a good job has a lot to do with my problem, but I have also been told that welding the wire directly to the contact is more reliable.

I will check out your suggestion for the brazing. Thanks!