What's going on??

[Bluebell]

Hi everyone

Here's what happened......   I've been trying different ways of finishing fused pendants without using a glue on bail .......too many disasters and they just come off!

So, I've tried:-
coated wire through the glass - very good result
fine silver wire making loops in the glass - very good result

Then I read about the compatibility of other metals when fused with glass and I came across this article which stated you could use sterling silver - well I've heaps of that, so decided to experiment. Ok they needed a bit of cleaning up - but end result is fine. 

First fuse great, second fuse great - third fuse disaster!

The only thing I can think that was different was the temperature.  I put the pendant in the kiln last night and the kiln temperature reading when I switched it on was 32 deg F which I think is zero deg C.

This morning, of about half of the 20 I put in, the glass has cracked and separated around the silver like a round button shape i.e. the glass has detached itself from the encased silver - does this make sense??

I know when I was preparing them for the kiln with the glue, I had to stop and work somewhere warmer (I think it was about -2 deg C at that time) and I only returned to the "ice box" when I was ready to load the kiln.

What do think is going on here - has anyone come across this before?  Is it the temperature? or something I've just not experienced until now?

[Pat from Canvey]

I don't know what's going on but you can use copper wire if the colour scheme will allow it. With transparent glass, I've made the ends of the wire more fancy with whorls as they show up. The copper does discolour in the part that is not in the glass but can be cleaned very effectively.

[Bluebell]

It's a real puzzler!

I've used copper wire (wrapped in thin fire) and it works a treat. And I've used fine silver.

However, the fact that I've done this process (firing sterling silver with glass - embedding it into the glass) tqwice before and and its worked fine is really confusing me.  The only thing that's been different is the weather and sub zero conditions.

Just wondered if that's something that folks have come across - OR.......am I thinking this because I haven't come across other reactions from sterling silver before and it was just something waiting to happen??

[Margram]

That's a bit of a pain. Wonder if it was condensation due to the change in temperature - don't know if this would be a
problem, only that I was told to allow glue to dry before firing...

[Mary]

I don't fuse, but I know too much silver in beads can make them crack, due to incompatibility. Could it be too much silver for too little glass?

[Bluebell]

Thanks for the replies.  But it has happened again. 

I took the advice about the condensation and in hindsight, yes the glue may not have been dry, so I made absoluetly sure that wasn't the case.  But after firing the glass has a button sized crack on the back.

Just to recap.... as I mentioned before, I have been so fed up with glued on bails pinging off that I just don't trust any glue now.  Having said that, I've a load of sterling silver leaf bails that I need to use somehow.

I read that fusing with sterling silver was ok but to be prepared to clean up the silver, which I can do and that's not a problem.  So I've been glueing the bails in between layers of glass and fusing.  The first ones I did were fine (96 coe) and a few 90 coe ones as well, but I've had this cracking problem.

But like Mary says, could it be that its just too much silver for a piece of glass that is only about 15mm wide?  I'm using medium and small size bails.

Any other ideas? or has anyone tried this and experienced the same?

[Zeldazog]

What sort of bails are you using, and why not post us a pic so we can see what's happening?

In my experience, too much/too thickness of ANY metal inclusion can cause what I *think* you're describing - I have fused a tube top into layers, but I would think a leave bail would be way too thick.

[Margram]

The funny thing is that you said "First fuse great, second fuse great - third fuse disaster!" If you
have had success before, then there must be another factor...

[Bluebell]

Hi

Tried to take a photo today, but something has gone wrong with my camera and I'm not techy enough to figure it out in a hurry!  So I'll describe a bit more. 

I had a load of pendants (6mm thick/full fused) about 40mm long by 12mm wide which had sterling silver leaf bails (medium size) glued on the back, but the glue failed and they all came off.

I have read that sterling silver is compatible with fusing although you have to clean up the silver a bit, so rather than discard them (the bails), I experimented with adding on an extra 2mm layer of glass on the back and sandwiched the leaf bail in between (held by a spot of superglue).

My first experiment was on a pendant made from 96COE glass which worked perfectly.  I tried again with 90COE and it worked again.  So on my third attempt a filled the kiln and most have a "button shaped" lump of glass which has either broken away from the back of the pendant revealing the back of the leaf bail, or you can see a very visible circular crack which will come away in time.

Having read all the replies, yes, it may have been that the glue was not dry enough and there was condensation, but on my fourth attempt I made absolutely sure that they were bone dry and still the button shaped cracks appeared. 

There have been sub zero temperatures outside, but I have been making sure that the kiln temperature has been well below 100 deg F before opening the lid.

I'm interested to find out how much sterling silver the glass will tolerate before it rejects it.  I have no problem with fine silver loops, but just didn't want to waste the bails that I have, so I'd really like to hear if others have experienced this. 

Thanks very much for all your replies so far.

[Zeldazog]

I am inclined to say that you were quite lucky that the first and second ones worked, rather than unlucky that the last batch didn't. IMHO a leaf bail is way to thick to fuse into glass.

Personally, I wouldn't try to fuse anything thicker than around half a millimeter in between glass, unless I was going for much thicker, more like casting.

At fusing temperatures, I am not convinced that the silver is fusing to the glass anyway - not like when fine silver wire is used on a bead - temperature in the flame is much hotter, and it melts the silver.

I could be wrong, but as far as I know, all that is happening in fusing is it gets sandwiched between the glass as it fuses around it, not that the silver is actually fusing to the glass?  I know copper doesn't actually fuse TO the glass (try leaving copper sheet exposed, it flakes off if not completely sandwiched) - so I assumed silver was the same.

The usual problem with glue not being dry enough is bubbles as moisture has tried to escape after the glass has softened, as you say condensation.

[Zeldazog]

"When working with metal inclusions, it is critical to use only thin foil or leaf thickness in order to allow the glass to contract and expand normally. Thin wire can also be used if desired."

From Warm Tips website