contact material

[junkhound]

Repairing anode contact of a Toyota starter,
I know, just buy a new starter, but easy fix and save $100+$$

The anode side of the starter relay contact eroded enough so that consisten contact not made.

Options for repair (cannot find a source for just the bolt and copper ring)

a. surface weld on copper to eroded area - high risk of damage to bolt

b. just silphos filler on the eroded part.

c. I have coin and 99% silver pieces, silphos15 silver contact area to existing bolt

d. straight brass braze rod. filler

The erosion is due to anode arcing, the motor side contact erosion is minimal.

Anyone with arc resistance of these methods?

 

[Jraef]

Cadmium used to be added to contact material to decrease damage from arcing, but that’s been outlawed (hazmat). I don’t know what they use as a substitute.

 

[jim dungar]

Cadmium used to be added to contact material to decrease damage from arcing,

Yes. Contacts for different purposes, like capacitor switching, magnetic ballast switching, or resistance heating, were often made of different materials, they almost never just copper. This is why instructions usually say to not file contact surfaces.

 

[rambojoe]

Just get the contactor only from napa and do what you need...
Heavy duty ones are great.