Help, what happened to my aurae?

bluefairy · August 22, 2009, 10:42:09 AM

Hmmm, I've been playing with aurae (a LOT!!

) and got some beautiful colours, really pleased with them.

However

Put them in the kiln to batch anneal and some (not all) have come out much more a sort of milky, mother of pearl colour. They're still pretty, but I've lost some of the beautiful colours I had before.

Any ideas what I've done wrong? I annealed for an hour at 515, my kiln tends to fire a bit hotter so I lowered the temp slightly from the annealing temp I found on here.

Lloki · August 22, 2009, 03:24:52 PM

I've read something somewhere about this Helen, might have been on WC?
I think it might be something to do with the amount of time you worked the glass in the flame before annealing, did you work some longer than others maybe?
It's definitely time/temperature related I think - doesn't help much - sorry!

Trudi · August 22, 2009, 03:59:09 PM

if they're encased you will get the MOP effect ....

Chameleon · August 22, 2009, 05:34:04 PM

Helen, Im guessing the ones that changed colour were un-encased ? Just wondering if you have a bit of a reduction atmostphere in your kiln if it could have caused them to reduce further ?

Sulis (Hazel) · August 22, 2009, 06:37:21 PM

I was just wondering how you were getting along! I passed your place on the way to Ikea last night and it hadn't burned down, so I figured that's a good sign

Becky, if you've got a slightly reducing atmosphere in the kiln, can you stick a bit of reduction sensitive glass in on it's own and see what happens to it to test it? I reckon you'd know stuff like that

I remember reading somewhere that you can change the atmosphere in your kiln by putting a bit of something in there when you fire it, but can't remember what?! Doesn't help much does it - what am I like?!!

Post pics of your Aurae beadies if poss - I'll bet they are fab! xxx

Les · August 22, 2009, 06:50:40 PM

wasn't it charcoal ? or have I got that wrong

Sulis (Hazel) · August 22, 2009, 06:51:54 PM

You know what Les, I was just thinking that but I wasn't a hundred percent sure I remembered right

xx

Dragonfire Glass · August 22, 2009, 08:35:07 PM

yes, charcoal

Redhotsal · August 22, 2009, 09:36:06 PM

Charcoal will make it more reducing because it "absorbs" the free oxygen in the kiln (and it also absorbs mingy smells!). That's one of the reasons you have to bake your bronzclay in activated charcoal so that it looks bronzy (i.e. brings out the metal)

From what I can gather it seems more usual to have an oxidizing kiln.

I reckon it is temperature related - but a more cloudy - MOP-y effect is probably 'cos it's over reducing. Try doing the same thing but don't reduce it as much before it goes in the kiln. Report back if you can - just to see if it works or not!

bluefairy · August 22, 2009, 10:50:18 PM

I think it probably is over reducing - they were all encased, and there was nothing else in the kiln. I'll take some piccies tomorrow, I know some of the beads I just wafted through the reduction flame and they came out metallic straight away, whereas some others took a bit more wafting before getting the metallics out before encasing. I bet they're probably the ones that have gone more milky now!!

Moral of the story - make notes whilst working!!