Annealing Beads, Garaging versus Batch - pros and cons

I've changed my annealing habits lately and have been considering the pros and cons of batch annealing and garaging.

All beads should be annealed, no question there - especially if you are going to sell them.  Small beads might survive without annealing but you'll never know for sure!

Batch Annealing

[caption id="attachment_1099" align="alignnone" width="450" caption="Batch annealing beads"][/caption]

I started out with this method as I didn't have a kiln.  Batch annealing is exactly what it says it is, you save up a batch of beads then anneal them all together by slowly bringing the kiln up to temperature, letting them soak and then slowly bringing the temperature back down.

What does this do?  This allows all the stress that has built up in the glass during the bead making process to dissipate, thus giving you a stronger more durable finished bead.

Garaging

I recently started garaging out of necessity as I found my cake testers would crack if I batch annealed them.  This must be due to the different expansion rates of the glass and metal rods.

Garaging means heating your kiln up to temperature - mine is around 900 - 950, then adding beads directly to kiln as you go.  The kiln is held at the working temperature until you are finished bead making and is then switched to the soaking temperature for a period of time before slowly cooling down.

[caption id="attachment_1100" align="alignnone" width="400" caption="garaging beads - yes, I know there are none in there, but wanted to add a picture for interest ;)"][/caption]

A good link for programming digital controls can be found here on the Wet Canvas forum - thanks to Lori Greenberg for sharing that information.

So - the pro's and cons?

Whichever method you choose, if you do it correctly  your beads will be annealed and should be of equal strength.  As far as I am aware one method does not exceed the other in the quality of annealing.

Batch - pros

• not using the kiln every time you make beads


• can make small quantities of beads at a time without feeling like you are wasting electricity

Batch - cons

• need to cool beads very slowly in order that they don't crack


• larger beads and sculptural beads are more prone to crack


• beads may crack while waiting to be annealed - I'd recommend waiting until after they are annealed to clean them, I think cleaning them in their non-annealed state is more likely to cause them to break


• I end up with piles of non-annealed beads, I find it interrupts the process and makes it more difficult to get a good production feel going.  I'll take pictures of beads before annealing and then find that the actual annealing and cleaning process is anti-climatic

Garaging - pros

• process is streamlined, beads are complete when they leave the kiln and just need cleaning


• safer for larger and sculptural beads


• kiln may also be used to keep bits of sculpture hot, enabling you to add them to the piece without so much fear of breakage


• if your workspace is cool, or cold you can keep rods of glass warm on top of you kiln

Garaging cons

• you use your kiln every time you torch, probably shortening the lifespan of switches and elements


• it seems wasteful to make only a few beads

So, which will I use in future? - Both!  I can see applications for both, although I must admit I am really enjoying the feel of having completed beads at the end of the same day they are made.

Japanese Annealing Bubbles

[caption id="attachment_1098" align="alignnone" width="300" caption="Japanese Annealing Bubbles"][/caption]

there’s a product on the market called Annealing Bubbles, while these ‘bubbles’ don’t actually anneal the glass, they do aid in making the cooling time a lot longer than with a fiber blanket. This is a good thing because it means your beads are less susceptible to cracking as they cool.

Here’s a link to a thread on this topic on the Lampwork Etc. forum and if you scroll down this page you’ll see the bubbles for sale.

I’ve heard good feedback from friends who are using these, and it’s definitely something worth considering.

Does a hot crock pot help? I’m very doubtful about this, a crock pot heats to quite a low temperature and given how hot the glass is when a bead is finished and comes out the flame I don’t think the temperature of the crock pot is going to make much difference.

Have you got pros and cons of batch vs. garaging? I’d like to hear them! I know when I started out beadmaking there was so much to learn about things that I’d never even dreamed of before, and annealing was one of those great mysteries of life!

Somewhat like this -

[caption id="attachment_1101" align="alignnone" width="425" caption="Raff in Space"][/caption]

Cracking Beads Gromit!

If your name is Wallace you might mean this as a compliment, and Gromit might be glowing with pride and joy. Unfortunately this post is not so happy, but hopefully might help explain some of the reasons that glass beads can crack.

Here is the reason I am writing this post -



'Tis a sad sight indeed! This picture explains why glass beads should be annealed!! I did not drop it, and didn't hear it crack when I put it down so can only assume it cracked all by itself.

I'll explain a little -

When I make my beads I save them up and then 'batch anneal' them. This means that they all go into a kiln together for a nice hot soak. Much like a hot bath can relieve the stress of the day for us, a soak in a kiln relieves stresses that have built up in the glass during the beadmaking process. - Well, it's not quite the same process, but it seemed like a good analogy!

This was one of my favourite beads that I was waiting to have annealed - I'd been wearing it because I liked it so much and you can imagine what a shock it was to find it in two pieces. The stresses in the glass were just too much causing it to split in two.

I decided to write a post for new beadmakers and bead purchasers to help explain why annealing is important and also some other things that may cause a bead to crack. The above picture explains the annealing part of the post and the following pictures will explain a few other things that can happen.

When a bead is made the glass is subjected to extreme heat, depending on the design of the bead the heat may not be distributed evenly through the glass. As the bead cools and stress is introduced 'thermal cracking' can occur -



At least this is what I believe has happened here. The bead has cracked in half along the mandrel hole in a nice clean line. If this happens the bead might fall apart before it even comes off the mandrel, or you might notice a crack that causes the bead to fall apart soon afterwards. I have noticed that keeping a bead in the cooler part of the flame longer once it is made reduces how often this happens. 'Garaging' or putting your beads straight into the kiln may also prevent this.

'Incompatibility Cracks' are quite different. I had to experiment here as I'd never actually seen one of these.



You can see that the two beads have broken apart into small and larger pieces that have no uniformity to them. These beads were made by mixing two glasses of differen't COE's together - the glass is incompatible.

I've read that there is a 5% rule when mixing incompatible glasses, that you can put a higher COE in small quantities over a lower COE but not vice versa, and also that even glasses of the same COE can be incompatible. If you want to know more about COE's and compatibility click here. Generally speaking if you use one type of glass in a bead you should not have problems.

On to perhaps the saddest of the cracks - this one I'm calling a 'Stupidity Crack'



It looks much like a thermal crack but has a different cause. This crack was caused by cleaning the bead too roughly with a diamond bead reamer. I've done it more than once, so I am convinced of this. If you are using a diamond reamer to clean your beads - be gentle!! I heard a 'ping' as I rammed the reamer far too roughly (say that six times fast!), and the bead fell apart in my hand.

So, there are my sad pictures for the day.

If you buy beads. . .

If you are someone who buys beads I hope this will explain why some glass beads may seem more expensive than others. Glass bead artists who take pride in their work know the importance of annealing and will usually mention it in their information. They are also aware of the different types of glass and which can be used together. The old saying rings true - you get what you pay for. Many imported beads are made from inferior glass and have not been properly annealed, they are likely to crack and have very short lifespans.

I will not sell beads that haven't been properly annealed. If you see new beads or beads listed as 'coming soon' in my blog and site you can rest assured that before they go up for sale they will be annealed.

If you make beads. . .

I hope the pictures help to show some of the differences and similarities in cracked beads. I am not an expert, and only sharing what I have learned so far. I am happy to receive comments, there is so much to learn!