Using PMC on Sterling Silver and Copper

[Maddie106]

I've been experimenting using syringe PMC to "Draw" on sterling silver, with limited success.
So far, I've found it best to make the PMC design, fire it in a kiln and then solder it onto the sterling using solder paste. I've not tried PMC on copper yet.

Has anybody got any tips or ideas please?

Chris Hannett

Daisy Lee Jewellery

[MuranoSilver]

You need to raise the fine silver to the top of the sterling by repeatedly oxidising, pickling and cleaning it.
Once it stops oxidising then you'll have a nice fine silver layer that your paste will fuse with. Don't fire too hot or too long as you'll be permanently weakening the sterling silver.
nicola x

[Lindyloo]

That's good advice Nic. Can you explain exactly how you tell it has stopped oxidising. And I've never heard that about weakening the silver. Can you explain the science behind that.

[MuranoSilver]

To prepare sterling silver for adding PMC you need to raise the fine silver by depletion gilding. Heat and pickle your silver piece several times it should look almost white (when you heat it and it doesn't darken it's ready) Clean the piece well after it's final pickling.

The kiln heat makes sterling silver brittle, you can add sterling while you are creating your PMC/ACS piece but you will need to fire at under 700 degrees C and not for an extended time.... This is because at higher temperatures, the structure of sterling becomes brittle.

[Lindyloo]

Thanks for that explaination. Do I take it that enamelling is done at a lower temp than PMC firing?

[MuranoSilver]

Nope - Dependant on the enamels they fire between 750 and 850 degrees C.
So I'd avoid using sterling inclusions on anything you plan to enamel, what are you thinking of doing? Could you use fine silver for the attachments or use enamelling solder to attach the sterling ones (after the PMC was fired)