Saturday, December 1, 2007

Batch Annealing And You (Because I Won't Do It)

Now that you know a bit about kilns and the annealing process, you should probably know that there are two schools of thought on how to anneal--Immediate and Batch Annealing.

Immediate Annealing

When using immediate annealing, after the bead is created in the torch and has cooled sufficiently to no longer be molten or soft, but is still very hot, it is put directly into pre-heated kiln and starts to anneal, you guessed it, immediately.

In my kiln I have a Kiln Couch (this where I got (scroll down a bit)), which is a rack that allows beads to be placed into the kiln so they do not touch the floor or the other beads. After I've made several more beads or when the racks fill up, I move beads to the floor of the kiln where they can now safely touch each other without any worries.

This is the safest method of annealing since the risk to breaking or cracking of the bead is very low once it has been placed into the kiln. Since I make some very large beads in addition to smaller ones, this method is really my only option in order to ensure that all the beads come out of the kiln as they went in--in one piece.

Batch Annealing

During this type of annealing, the kiln is even turned on while the lampworker is making their beads. When a bead has been completed, it is placed either into a hot crock pot of vermiculite or (worse yet) a fiber blanket.

Both the vermiculite and the fiber blanket slow the cooling of the glass in an effort to prevent the stress from breaking the bead as it cools. While the crock pot does add heat to the vermiculite, it cannot approach the temperature needed to actually anneal the beads.

Once a group of beads is ready for annealing at some point in the future, they are all placed into a kiln which is then slowly heated to the correct temperature for the annealing process. Once the kiln is back at room temperature, the beads have been annealed and are ready for use in jewelry or other applications.

It is not uncommon for this process to result in a few broken beads when the process has completed simply because the stress in the beads could not endure being reheated in the kiln.

This type of batch annealing is most often employed by new lampworkers or lampworkers who do not yet own a kiln of their own., but there are many lampworkers (that also own kilns) who swear by this process. For me, I've never been comfortable with gambling the life of my beads on a crock pot.

If you have a different point of view, have any questions or would like to suggest topics, I can be reached through this blog or through my web site or shop at:

Thanks for stopping by!

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