Page 1 of 1

Silver Motor Contacts

PostPosted: Mon Dec 17, 2012 11:03 pm
by MUTiger
I have a bag of silver motor contacts that is about 400 grams. Can anybody tell me what the typical silver content is on these types of contacts? Who on this forum turns these into cash, Market Harmony, Dr. Cadmium?

They are from a friend in the electric business that knows I like scrapping.

Thanks,
mutiger

IMAG0276.jpg
Silver Motor Contacts
IMAG0276.jpg (26.9 KiB) Viewed 1145 times

Re: Silver Motor Contacts

PostPosted: Tue Dec 18, 2012 5:40 pm
by scrapman1077
You need to unsolder the contact from the carrier, this will reduce the 400 grams, but keep saving them up! Yes I will trade these for silver rounds once you get some more.
Jay

Re: Silver Motor Contacts

PostPosted: Tue Dec 18, 2012 8:48 pm
by messymessy
I think the contacts are silver mixed with graphite or silver mixed with tungsten, but I don't know what percent silver.

I saved them for a while but found them very difficult to unsolder.

Re: Silver Motor Contacts

PostPosted: Tue Dec 18, 2012 8:53 pm
by Rodebaugh
Dad has a few of these. Maybe he can explain how he removed them from the brackets.

Re: Silver Motor Contacts

PostPosted: Mon Dec 24, 2012 9:27 am
by Dr. Cadmium
You need to separate the silver contacts from the bus bars, which are usually copper but can also be made of brass or steel.

To do this, you'll want a mapp gas or oxygen-acetylene torch, definitely the later if you have a lot of material to go through. You'll also want a full-face respirator because of the dangerous fumes. I have read that many, if not most of these contain cadmium in the solder but I do not know for certain.

Apply heat to the back of the bus bar where the silver button is and heat until the section is red-hot. Then use a thin-edged tool like an old kitchen knife to slide the button off. With a little practice, this takes minimal force. You shouldn't have to tap or bang the piece to free the slug; if you have to do this you need to heat the piece hotter before trying to separate it.

These buttons are usually 90% silver or better. Not all refineries will take them, and those that do seem to either charge a higher processing fee or return lower results (I assume because of the cadmium and other contamination).

The ones with patterns on them that look like waffle irons are usually only 40% silver and the rest is partly or mostly tungsten. These are obviously more difficult to process.