Three types of contacts

[kurtak]

Here is the pure Pd points .7 gram & the silver 1.9 grams I got from doing the demo for Jon --- I believe that was from 9 of the relays - maybe 11 relays - don't remember exactly just remember it was an od number of them

 

[g_axelsson]

Great demo Kurt! Thanks for sharing! 8)

I also went thru a literary ton 25 years ago. It was during the time when old relay based telecom equipment were replaced with new digital ones and the scrap yards were full of the old racks. I got a good deal that if I dismantled and sorted the base metals I could have the points for free.
The difference from Kurt is that I hand snipped all the points. I sat in my apartment on the evenings and cut them off, one by one, while watching TV. I even had some friends that helped out just for fun. In the end I got almost two kilos of contact points.
I did a few feeble trials and refined 20-30 grams of silver in a primitive silver cell, but as this was before the web was borne, information was really scarce and I was experimenting on my own.
I still have all the contact points somewhere in storage. I last saw them 7-8 years ago so I know they are still with me but I think they sit behind a ton of stuff, just waiting for me to rediscover that box with all my silver in it. :lol:

Thanks to you Kurt I now have a plan how to sort the silver from the palladium points. Maybe even fulfilling a dream I had as a boy of making a 1 kilo silver bar from silver I collected myself.

I like this game. Kurt gets to teach me and I'm a willing student when I'm out of my "zone." 8) 8)

Göran

 

[Anonymous]

Haha! Touche Goran 8) 8)

 

[g_axelsson]

That's what so great with this forum, we all learn some new tricks now and then. 8)

Göran

 

[UncleBenBen]

Thank you indeed kurtak!

I've got several hundred of those and similar relays to get to eventually. Definitely going to be tossing this thread to favorites folder!

 

[Geo]

I have held many of those contacts. They are a high percentage palladium. You can test but they look exactly like the ones I have processed. Huge metal frames with several hundred switches per. Most have a wound copper solenoid and every twentieth or so will have half wound/half solid copper solenoid. The main difference is the gold plated points and the bright silver points. Silver tarnishes black and the palladium points tarnishes gray. The cable ends should have pin connectors that at first glance looks like tinned brass or copper but the tips have a small, pure gold pad. They yield much better than fully plated pins.

 

[Anonymous]

Geo

My thanks.

Jon

 

[solar_plasma]

This thread made me curious, so I made some photos to see and to show differently tarnished contacts. All of those relais have been used, so none of them is new.

 

[vgecas]

Helo,

Once i had some potentiometers (soviet made) that had sliders made from Pd alloy. Some sliders were 70% Pd, some were 30% Pd and some contained no Pd at all. Quickest way to determine if slider contain Pd was to heat it red hot with propane torch and cool it down. Those, that contained Pd (even 30%) after cooling stayed bright, those that contained no Pd - tarnished.


P.S. sorry, English is not my main language.