Bullseye Bead Annealing Schedule?

Started by *rowanberry*, September 15, 2007, 01:15:04 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

saffie

Mmm...ok will check out my schedule on my kiln currently. this was the schedule (except for my high temp!!!) on bullseye website! I don't generally batch anneal anymore I work to the kiln. I ramp up over about 45 mins to garaging temp hold for however long and then control ramp down to 360 and then kiln goes off. So this should be completely fine for my bullseye cool!!!
BTW i go up to 540 cos i thought and I am sure i read somewhere that effetre strain point was 537??? Am I wrong where the blazes did i get that!
Going to play with bullseye tonight, Have got polarising lenses from Sal so can do the check anyway!!
Thanks for your input guys much appreciated
Sam

Rachel

Quote from: saffie on November 10, 2008, 08:30:00 AM
BTW i go up to 540 cos i thought and I am sure i read somewhere that effetre strain point was 537??? Am I wrong where the blazes did i get that!

Hi Sam

I think the problem is that there seems to be no definitive answer out there - however this is a good piece on annealing by Mike Aurelius

http://mikeaurelius.wordpress.com/2008/01/30/garaging-and-annealing-two-different-aspects-of-the-same-beast/

:)

silverlemon

Quote from: Rachel on November 09, 2008, 11:20:39 PM
although I don't think I'd be brave enough to go Sarah style and do it in 20 mins ;D 


;D ;D ;D ;D ;D

I've been doing all this again this week cos I just got my grubby mitts on a Maxine the other week and have been checking facts and figures and doing programmes myself too.

I found this really useful website by Kim Osibin who's been lucky enough to visit the Effetre factory, so I hope her information is correct. There seems to be so much bogus stuff about.

Here's Johnny...sorry, here's the link http://www.flameworkedbeads.com/WorkingwithEffetreGlass.html   

The strain point is 840 deg F which equates to 448.9 deg C.

The softening point is 1050 deg F which is 565.5 deg C.

I too wouldn't programme in 540 for annealing as it's close to the softening point and it''s really important to remember that just cos your kiln says it's a particular temperature, doesn't mean it is that temp everywhere. All kilns have hotter and cooler spots by virtue of their design and the characteristics of the elements. So while it may say 540, this may be the cooler spot.

My old kiln had the thermocouple at the hot end (fortunately) and I had a drop of 30 degs across the length, so I knew where to put my bead if I wanted a higher temp.

If you're working into your kiln as you go, why not just wack it on full blast to reach garaging temp and leave it to settle before you start work?

HTH  :D
Bionic Sarah xxx    Sarah Downton On Facebook  My Etsy Shop

silverlemon

Hmmm, interesting.
Just had a look at Rachels link.
It's funny how there's so much conflicting information.

I thought that actually there was no annealing temperature as such, but an annealing range, the same as the coe of Effetre is not actually 104 but in the range eg. Effetre transparent and pastel are 104 to 106 with some exceptions in these groups being 109 to 113 (explains why red isn't very comaptible...ahhhh). Special colours and opals are 109 to 113...again...ahhhhhh.... ;D

So how can there be a set temp for annealing?
and actually why not garage at the annealing temp?

I've actually always set my kiln at a lower garaging temp, about 60 deg C less, but only so the kiln didn't overshoot the annealing temp when I opened the door.

Lots to think about

Actually it's really helpful that there's an annealing range (this is what I go by anyways) because if you do have a temp gradient across your kiln you can have one end of the kiln at one temp, and the other end at the other temp. woohoo.

I can't help but think the reason everyone uses different schedules isn't actually because they're annealing at different temps, but because their kilns have different charcteristics and they're compensating for that.

I'm waffling now.....must go and do some work.....but it's yukky out there and I have to cross the garden  :(
Bionic Sarah xxx    Sarah Downton On Facebook  My Etsy Shop

saffie

OMG what a minefield! I am not sure where I got my kiln schedule from but it was on here i think some time ago! Yes i upped the temp to compensate for CIM but just reading the thread on LE and this is tricky, annealing temp for one glass in CIM can be slump temp for another the range is vast!!!

So.....what i have decided i to reduce the temp i garage at and extend the time my beads are in the kiln for! I generally leave a hour or so at the end of my session before the kiln begins to ramp down. I will reduce the bottom end temp down to 300 or so and then let the kiln cool naturally.

Pat from Canvey

Quote from: silverlemon on November 09, 2008, 10:51:32 PM

I'm wondering why you're taking so long to ramp up for batch annealing (I never understood why everyone uses such slow ramp ups for batch annealing, I've always just turned on my kiln and let it get to temp in 20 mins, nothing has ever broken, although you may want to slow it down as you get nearer the anneal temp so the kiln doesn't overshoot).

I've always done this too in my bead kiln and have never had any problems with breakage. The only times I've used a slow ramp up is when I've been firing clay to bisque in my big kiln.