Kiln times

[Im a glassy babe]

Hi,

Yey! I've eventually programmed my kiln to batch anneal some of my beads.  Not sure how it's going to turn out, but we'll see.

Question is how long roughly does the sequence take.

I've used the following schedule:

Ramp1 149C
Temp1 520C
Hold1 60mins
Ramp2 78C
Temp2 371C
Hold2 0000mins
Ramp3 0000

Hoping this is going to be ok.  Feel very brave turning it on, only taken me about 8 weeks.

All the reading on this forum helped me to understand much better.

x

[Redhotsal]

Approximately 6 and a half hours.

[shallybags]

Ooh err,

I've only had my kiln for a few months and I have set it up to run an annealing schedule that takes approximately 3 hours.

My kiln heats up to 480 degrees in just over 30 mins, then slows down to heat up to 520 in about 10 minutes, I hold the temp for 15 minutes and then cool slowly down to 360 degrees and then cool more quickly down to 50 degrees.  I forget the rates right now.  But altogether about 3 hours from start to finish.

Most of my beads are smallish, donuts, with a few barrels and bicones occassionally.  I am annealing for a friend as well, so I'm concerned that I might not have the schedule right.

What do all you lovely people do? 

(I have to say it was pretty difficult to decipher the instructions that came with the kiln.  Most of the printed information didn't apply to my model.  I found the rest of the information I needed in Bandhu Dunhams book.  It took a whole Saturday afternoon to read, understand and programme.)

Shallybags

[Rachel]

Shallybags - are you batch annealing?  If you are I think that going to 480 in 30 minutes might be too quick.  It's a while since I batch annealed but I'm sure it should be brought up to temp more slowly.

I can't remember my schedule off hand but I hold after the last bead has gone in for around 30-45mins then ramp down to something around 468 ish and hold for 30 mins then ramp down slowly to 250 and then off.

 

[Zeldazog]

I Thought the ramp up looked a bit too quick too, fr a batch anneal - but I not a bead expert, so I not sure.

Of course, if you're sticking your beads straight in from the flame, the heat up rate doesn't matter.

The anneal soak doesn't sound awfully long either, to me.  I would expect there's quite a lot of stress in a bead?

[shallybags]

Good job there are people out there to ask!

Yes, I do batch anneal.  My space is limited and after working next to my kiln whilst it was working I got too hot.  When I finally get into a workshop I will probably run my kiln while I'm working.

My beads are all quite small and I tend to flame anneal, I cool them in a fibre blanket sandwich that I have wrapped in aluminium foil.  So far none of the kiln annealed beads have broken.

Is there a definitive source for annealing schedules that everybody uses?

Shallybags

[Pat from Canvey]

Am I right in thinking that the larger the bead, the longer the hold times need to be? I generally hold for an hour and then ramp down.

[Rachel]

I don't think there is a definitive schedule as such - there are some posted in the tutorial section on here.  Or you could trry a search on Wetcanvas or Lampwork etc.  Effetre strain point is around 840 F /448 C so as I understand it you need to cool slowly down to that and hold for a while - I hold for 30 mins. Then you can ramp down from that.

[shallybags]

I've been at the books again  - a nice Sunday, reading about lampwork punctuated by watching the olympics. 

I initially set my annealing schedule up for beads that are no thicker than 1/2 inch, so that's why my schedule is so short.  However, after all the reading this weekend and your comments I will have another go at creating a schedule.  I'll go hunting on the forum as well and read up as much as I can before my next run.

Thanks folks.

Shallybags