[emfrebuilding]

Currently we silver solder motor brush leads (stranded copper wire) to the stator bars in motors but this requires a lot of care on heating and the flame path. What I wanted to try was tig welding( or using the tig as a heat source) to braze or weld these leads onto the wire. The factory uses spot welders but a complete teardown is required and I want to avoid that.

Anybody tig copper to copper?

thanks

Jim

[Otto Nobedder]

Welcome, Jim,

It can be done, and those with copper experience will (sooner or later) comment, but I'm leaning toward the idea of using a TIG power source to compression-spot-weld, because the braid will behave as very fragile under a TIG arc.

How big/wide a braid to how broad/thick a bar? I'm thinking through how I'd attempt/experiment this, and size matters...

Steve S

[emfrebuilding]

the braid is about 3/16 in diameter and the bar is about 1/8 thick. It is the field winding which is usually made, at least in large starters, out of 1/8 or so thick by about 1/4 wide. flat wire can carry more amps and is easier to wind in tight coil form. I figured I would press the braid in with some sort of clamp and hit it with the arc using silver solder for a filler when it got hot in the immediate area. that way I have an intense heat source without the side splatter of a flame.

I am going to try this out tomorrow and I will send some results.

[Drifta-X]

Could u over load the wire with solder and then place on the bar and heat?

[79jasper]

Could u over load the wire with solder and then place on the bar and heat?

I don't think that would get enough on it. It may though.
I'll tell you I've had to silver solder new brushes in the starter on my psd, that stuff takes a lot of heat to melt.
The guy I got the brushes/rebuild kit from gave me four little pieces of silver solder. Probably about 1cm^2.
I barely got if after trying many methods.
He had a "pinch" spot welder that they used. (It was a electric motor shop) But these days, those are hard to find.
Really I don't see why it couldn't be done with tig. But very interested to see if it works.

Sent from my SM-G900R4 using Tapatalk

[emfrebuilding]

I should probably rephrase the "silver solder" comment as that is high temp stuff the HVAC guys use. I meant to say silver bearing solder which melts about 600 degrees F.

[Otto Nobedder]

I should probably rephrase the "silver solder" comment as that is high temp stuff the HVAC guys use. I meant to say silver bearing solder which melts about 600 degrees F.

Ahh. Different animal entirely. I'd pre-tin the braid, and use a 500W gun and be done. No mess.

Steve S