exploding beads..

turnedlight · January 19, 2012, 04:13:12 PM

I had a lovely play today with some boro glass, popped it in the kiln on my normal garaging program for soft glass planning to anneal it hotter when I manage to work out how to put in a second program on my kiln (only had it 4 years

) and when the kiln came down they had all exploded or crazed into lots of pieces..
Can anyone tell me if this is because I didn't take them high enough annealing, only soft glass beads usually crack down the middle when it's a heat issue. Or does boro behave differently?

and ps, I have an sc2 kiln, and no manual - can anyone possibly take me through putting in a second program?

garishglobes · January 19, 2012, 04:27:22 PM

ummm......boro is usually very well behaved and thermally very patient. Usually, thermal cracks look the same as soft glass - straight down the line. If they've crazed into lots of tiny pieces, it sounds as if they've been mixed with soft glass

JKC · January 19, 2012, 05:00:05 PM

I've never had that happen either. Janet

turnedlight · January 19, 2012, 05:10:14 PM

I ordered it all together, and got it out of the box and used it straight away, so I know I didn't mix it with my other glass.. I thought it was odd, will contact the seller.

Redhotsal · January 19, 2012, 05:19:09 PM

You can check.
Take a rod of suspect rod number 1 and dab a really small amount of suspect rod number two onto it. Pull a really thin stringer at the join where the two glasses meet. About the width of a human hair... . Break off the stringer and drop it onto your desk. If the glass is compatible the stringer will remain straight but if they've/you've mixed in some soft glass the stringer will curve.
You can use this for checking whether any glass is compatible - but you should see straight away whether your glass has become "contaminated" or not.

turnedlight · January 19, 2012, 05:44:03 PM

Fab! I will try it!

Steampunkglass · January 19, 2012, 07:26:24 PM

The only time I've had that was with a rod of clear I wasn't too sure about, and the whole thing turned into broken glass like the stuff you normally find around broken bus shelters

The clear should be harder to melt and stiffer than the same thickness of 104 glass, clear seems to be what normally gets mixed in by mistake

turnedlight · January 19, 2012, 11:26:30 PM

That's exactly what the beads ended up like! Bus shelter glass - or like what happens when you 'kill' a bead that's going badly by putting it in the water jar

I didn't think the clear glass was very soft when melting it, but I was thinking that it wasn't nearly as hard to melt on one oxycon as people seemed to make out.. So maybe I was sent some 104 glass by mistake.. I will try the stringer test - it would be a shame if so, as I made some pretty nice beads for a first go and used up some precious coloured boro.. But at least it would be an explanation.

Pauline · January 20, 2012, 09:20:23 PM

I think I am being thick here but...if it is 104 by mistake instead of boro why would it explode on your normal 104 garaging programme???

do you want me to photocopy my SC3 manual and send it to you for info on changing programmes or has some clever person got an electronic version to you already?

SilverGems89 · January 20, 2012, 09:29:23 PM

because it was used with boro Pauline (coe 33...if my memory serves me correctly!) and as well know, mixing different coe's is never a good idea!

Pauline · January 20, 2012, 09:35:49 PM

OIC I was assuming it was beads made of 1 rod of glass rather than mixed...ooops

fionaess · January 21, 2012, 11:30:14 PM

I feel your pain

I had exactly the same happen to me this week = so called 4mm clear boro - fortunately I only made 2 small beads. I really should have known better though. I realised that my 4mm boro had been 'contaminated' with 4mm 104 stringers from my supplier when I ordered it, because the second rod I used did exactly the same - totally crazed glass. That was the reason why I never used it. Now all I have to do is find a 4mm supplier who can assure me that their 33 COE is just that !!
No, it wasn't me mixing them up - I have never ordered 4mm clear 104, never ever !!!

turnedlight · January 22, 2012, 09:21:30 AM

The bead cracked when slightly cooling out of the flame - I though it was funny as boro is supposed to be less problematic, but being inexperienced I just carried on. Bit cross about the coloured glass I wasted but luckily it wasn't much as I was being frugal.. I wonder if we both got the glass from the same place - time for me to let seller know, though I haven't had time to do the stringer test yet.

turnedlight · March 07, 2012, 05:45:25 PM

Yay, finally got around to going in my shed again, tried the replacement clear glass with the boro colours and it worked fine - thanks for all the help and thoughts!

Blue Box Studio · March 07, 2012, 07:48:56 PM

Quote from: turnedlight on January 19, 2012, 04:13:12 PM
I had a lovely play today with some boro glass, popped it in the kiln on my normal garaging program for soft glass planning to anneal it hotter when I manage to work out how to put in a second program on my kiln (only had it 4 years ) and when the kiln came down they had all exploded or crazed into lots of pieces..
Can anyone tell me if this is because I didn't take them high enough annealing, only soft glass beads usually crack down the middle when it's a heat issue. Or does boro behave differently?

and ps, I have an sc2 kiln, and no manual - can anyone possibly take me through putting in a second program?

Does this help? http://www.youtube.com/watch?v=QyJc0tiwi1Y If not I can go and get my SC2 instruction book from the shedio and see if I can scan it when at work tomorrow.