Annealing and kiln question
 

I make beads in the 14mm-16mm range and am wondering if, when I'm done with my normal 4 hour torching session, can I just shut the kiln off and let it cool down without the holding cycle I have presently? I want to torch early in the morning and don't want to have to stay home and babysit the kiln (Paragon Bluebird XL) ... are my beads small enough to be able to do this??

I have my kiln (Paragon) set for a 12 hour garage segment and a 2 hour (ish, my memory is not helping today) annealing ramp down to the strain point of 780 (again the memory thing) with a cool to room temp of about 6 hours.

My point is that I just skip to the next segment in the program and it starts the annealing part.

I also trust my kiln to do what it has been doing ever since I bought it just like I trust my stove and my washer and dryer. So I tell it what to do and go to sleep with concern.

I also have the protection against worst case with a clear bench around the kiln and smoke detectors in 3 places in the house and a circuit breaker on the far side of the room and 2 fire extinguishers.
So even if the internal protections of the kiln fail I still have confidence in my back up plan and my back plan to the back up plan.


I don't have experience with a Bluebird but I don't think it will hold the annealing range of 950 to the strain point long enough to properly anneal beads in that size range.

Maybe someone else will have a better idea of that.

Also I am wondering about your measurements. Is that from the mandrel to the edge of the bead or is that from one side of the bead to the other.

I think the hole in the middle of the bead counts as the start of the thickness when the glass manufactures measure the rate of cooling.

Maybe LarryC or yellowbird can help us.

Yes, I have mine set for an 8 hour garage segment at 940 and when I'm done making beads (usually 4-5 hours) I skip to the hold #1 which is set for 1 hour (or maybe 30 minutes ... my memory isn't that great either). The size of the beads are diameter ... just medium size for a jewelry bead. I'd just like to be able to turn it off and go have fun without worrying it might start a fire. I was told once by someone who knows glass, that since they were such small beads, I could get away with just turning the kiln off and letting it ramp down by itself. Hoping that's true!!

Well, The easiest answer is maybe :) You still have to soak within the acceptable range to anneal. If your kiln is insulated well enough so that it drops slower or at the same rate as a reasonable annealing cycle when crashed then it should be fine. Otherwise I would run the full profile to be sure. Why so worried about your kiln? You really should not have to babysit it.

Angie, why don't you try it one time and see how quickly your kiln loses heat? A fire brick kiln that's been at 940 for 4+ hours should retain the heat pretty well. It might not truly anneal your beads, but 14-16mm should be fine to run through a trial. I'm pretty sure they will survive with no thermal cracking. Then anneal them properly the next time you run a full cycle. If you're worried about the beads, though, run it empty to get a better feel for the rapidity of the heat loss.

Mimi

Just concerned there might be a fire ... I had a small one (well ... not that small) with a dropped bead onto some carpet and it scared the hell out of me. I'm just concerned since it's up at such a high temp. Do you not worry about yours? You don't baby sit it?

I've a Bluebird Jr and don't baby sit it. As long as it's placed properly (correct distance from the wall, fireproof base to sit on, etc), shouldn't be a problem. I tend to torch late; when I'm done I skip the rest of the garage time (I gave myself 10 hrs) and let it anneal. And go to sleep.

You stand a better chance of something fire related happening with your torch/fuel than with your kiln.

Last week there was a power outage here and my Bluebird XL lost 400 degrees in 45 minutes. This was during the annealing cycle. So I would say no. They weren't big beads. I reannealed them later by bringing up slowly, but some didn't make it, like the ones with silver wire on the surface.

Never.

The Bluebird doesn't hold heat well enough to just shut it off. You need to ramp it down to at least 500.

The "you can just shut it off" advice is only good for brick kilns, and even then, you should ramp to 800 before shutting off. The Bluebird is fiberboard, which isn't sufficient for that. While better that fiber blanket, it still doesn't hold heat in nearly as well as brick.

My Bluebird XL is a brick kiln, so hers might be also. Depends on what you ordered.

I typically use my Chili Pepper, and I leave it after I verify that it has started ramping down. It is about 16" away from the wall, sitting on ceramic tile that is on a wire shelf. And I always go back and check it when it should be off.

I wonder if there is some sort of add-on device that would be a shutoff if the temp got to be more than your holding temperature?

Are you selling your beads? Do you give them away including Beads of Courage? If yes, then no.

If you keep them all yourself, then you may take the chance of them not being properly annealed.

Kathy, according to Paragon site, the roof of your kiln isn't fiber brick but ceramic fiber board. So no, it doesn't retain heat as well as a fully fiber brick lined kiln such as a Glass Hive.

http://www.paragonweb.com/bluebird_xl.cfm

I have left the house with mine ramping down, but not often and not for long. I have heard of a malfunction where the kiln heated up way beyond normal when there was an equipment failure, but luckily there was a sprinkler system that kept it from burning down the building.
I may have a bit of that wrong, but the gist of it is correct.

YES IT IS CALLED A CONE SITTER.
however THEY ALSO CAN FAIL .