Fitting Galena crystal to cup - UK Vintage Radio Repair and Restoration Discussion Forum

PJL · 11th Sep 2016, 8:02 pm

I have found this thread here https://www.vintage-radio.net/forum/...ad.php?t=94220.

The crystal fell out of the holder on the set I am working on leaving a metal like material in which it had been set. Great I thought, it must be Wood's metal so I can melt it and reset the crystal. Various attempts at raising the temperature and it did nothing so I dropped it in water straight out of the kettle and it was still solid so I can only assume its solder!

I will scrape the material out under water to be safe and clean up the cup but then I am wondering what others have used to set the crystal. Field's metal is prohibitively expensive and I am not keen on using Wood's metal due to the cadmium content (it seems Russians are quite OK shipping it to us!).

I am thinking of painting the crystal underside with conductive silver paint, set it in a non-conductive filler, then paint over the filler with more silver paint and onto the cup edge. The only concern I have is if there would be any interaction between the silver and galena.

11th Sep 2016, 8:05 pm

Silver loaded epoxy?

JHGibson · 11th Sep 2016, 8:18 pm

Wrap the crystal with aluminum foil and force it into the holder.
John.

ms660 · 11th Sep 2016, 8:21 pm

I'm not sure or not if there will be any interaction between Galena and Silver, down here in Cornwall Galena and Silver are common bed mates as it were, Silver is found with Galena and was extracted from Galena ores.

Lawrence.

David G4EBT · 11th Sep 2016, 9:27 pm

As an alternative to Wood’s Metal, which was originally used to fix crystals in their cups, you can get specially formulated low temperature solder which melts at well below the 100 degrees C/212F temperature of boiling water – namely, at 70 degrees C/158 Degrees F. Here for example:

http://www.ebay.co.uk/itm/9inch-deso...QAAOSwqu9VBHxI

Might be worth a thought?

Hope that helps.

11th Sep 2016, 8:02 pm	#1
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Fitting Galena crystal to cup I have found this thread here https://www.vintage-radio.net/forum/...ad.php?t=94220. The crystal fell out of the holder on the set I am working on leaving a metal like material in which it had been set. Great I thought, it must be Wood's metal so I can melt it and reset the crystal. Various attempts at raising the temperature and it did nothing so I dropped it in water straight out of the kettle and it was still solid so I can only assume its solder! I will scrape the material out under water to be safe and clean up the cup but then I am wondering what others have used to set the crystal. Field's metal is prohibitively expensive and I am not keen on using Wood's metal due to the cadmium content (it seems Russians are quite OK shipping it to us!). I am thinking of painting the crystal underside with conductive silver paint, set it in a non-conductive filler, then paint over the filler with more silver paint and onto the cup edge. The only concern I have is if there would be any interaction between the silver and galena.

11th Sep 2016, 8:05 pm	#2
Guest Guest Posts: n/a	Re: Fitting Galena crystal to cup Silver loaded epoxy?

11th Sep 2016, 8:18 pm	#3
JHGibson Retired Dormant Member Join Date: Apr 2003 Location: Salt Spring Island, BC, Canada Posts: 368	Re: Fitting Galena crystal to cup Wrap the crystal with aluminum foil and force it into the holder. John.

11th Sep 2016, 8:21 pm	#4
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Fitting Galena crystal to cup I'm not sure or not if there will be any interaction between Galena and Silver, down here in Cornwall Galena and Silver are common bed mates as it were, Silver is found with Galena and was extracted from Galena ores. Lawrence. Last edited by ms660; 11th Sep 2016 at 8:21 pm. Reason: missing words

11th Sep 2016, 9:27 pm	#5
David G4EBT Dekatron Join Date: Feb 2003 Location: Cottingham, East Yorkshire, UK. Posts: 5,767	Re: Fitting Galena crystal to cup As an alternative to Wood’s Metal, which was originally used to fix crystals in their cups, you can get specially formulated low temperature solder which melts at well below the 100 degrees C/212F temperature of boiling water – namely, at 70 degrees C/158 Degrees F. Here for example: http://www.ebay.co.uk/itm/9inch-deso...QAAOSwqu9VBHxI Might be worth a thought? Hope that helps. __________________ David. BVWS Member. G-QRP Club member 1339.