Batch & hot off the torch annealing

[LauraLou]

I have read everything I could find about annealing, but I can't find info about what I'd like to do. I'd like to start out batch annealling and then add hot beads to the kiln straight from the torch. I have a brick kiln with a Sentry 3 key controller and I am annealing Moretti glass...
Should this program work?

(Put cold beads into kiln) Ramp up to 950 over 2 hours.
Hold for 4 hours (torch time).
After last bead goes in push 'skip program' to jump to the next segment.
Then
Ramp up to 960 fast as possible. Hold 1 hour.
Ramp down to 840 ober 2 hours (strain point). hold 15 mins
Ramp down to 700 over 2 hours, then turn off.

Also, what temp should the kiln be before adding the hot beads?
Thanks,
Laura

[Peach Blossom Beads]

Don't know why no one is answering, so I will...

That's perfect. Your kiln will already be at the right temp (950) when adding hot beads. Don't add them sooner though. You can ramp up a bit faster too, if you want. I do it over an hour or so and have never had an issue. Have fun!!

[LauraLou]

Thanks for the reply! However, I somehow goofed up the segment where it ramps down from 960 to 840 and it ramped down to 840 at a rate of 420 per hour and I also goofed up the next seg to ramp town to 700 and I ramped that one down at a rate of 350 per hour. This morning, the beads are ok, but I'm worried that they'll crack when I go to clean them. Should I re-anneal them? I'm not planning on selling them, I was going to make gifts out of them. When I unloaded the kiln this morning, I found a transparent bead that was left over from the last firing. Oops! I think it should be fine though, you can't over anneal, right?

Laura

[Sylvie D.]

Hi,

The annealing time needed to ramp up and to remp down to the strain point varies with the bead size. There is a very detailed table about this in "More than you ever wanted to know about beadmaking" from Jim Kervin (an amazing book: so far, I've always found answers there for any single technical question I could have!). I don't know if it would be ok for me to post the table here, but if you just tell me the average size of your bead, I can check it in the book for you and let you know. I'll just say for now that for Moretti / Effetre / Vetrofond glass, if you have a bead with one inch diameter, you could ramp up in 38.7 minutes at the rate of 22.5 F / min. You could also go more slowly of course...

[Cosmo]

No reason to hold at 950 and then ramp to 960. Just hold it at 960. Everything else seems fine though.