Boro softening temperature?

[noora]

I would like to try adding silver clay to lampworked items (beads if possible) and firing them a second time, but the glass will probably deform (slump) if I use COE 104 or 90 so I was thinking perhaps boro might work.

Would boro start deforming at 650 degrees C? It will have to sit in the kiln for half an hour or so at that temperature to fire the silver clay.

Has anyone tried this and already found it a bad idea not worth trying again? 

[Lakelady]

It will be fine with boro - just keep it off the kiln floor and don't rest it directly on a mandrel rest in the kiln 

[amareargentum]

I've done it with 104 and it has been fine. I followed some instructions on Rocio Bearers website on how to fire it. From memory it was at 600 C rather than 650C which worked just fine as it was only a very thin overlay of clay.

[Steampunkglass]

Softening temp for clear boro is about 1500deg F, so about 850 degrees C, and some of the colours/brands seem to need alot more so I think you'll be safe. You might find that one or two of the striking colours  may strike or re-strike at that temperature though, so for example some of the purples might go a little darker. Some of the reds can be a little sensitive, as they strike around 585-590, especially some of the earlier formulations. They won't change shape but they might go a more livery darker shade.

You might also get away with some of the 'bottle glasses' like beads made from old bombay saphire bottles. I've kilned those at about 730 for a short spell and they barely changed shape for me

[noora]

Thanks!  I only have clear boro so I'll try with that  Perhaps I can give 104 a shot too, maybe try it on some fuglies first. 

[sparrow]

I've done some on 104, too, at 600, for....45 minutes, if memory serves right??


Splash!! by Sabine Little, on Flickr


Howling wolf by Sabine Little, on Flickr

(don't look at technique, these beads are 4 years old!!!!)

[noora]

Wow, those are lovely! I thought soft glass would slump at that temperature since it's such a long time too, but obviously not