Monday, May 21, 2012

Cracked Bead Recycling

This is a re-post from the Beadful Life - I contribute regularly to the blog there too. 

Here is a little peek at a project I'm doing today. What to do with the cracked beads.

Beads crack because they get too cold (while you are admiring them or you are making too many at once!) before they go in the kiln. Perfectly nice beads, cracked in half. Some really nice beads, cracked in half. Such a shame!

So when you collect enough of them, you can put them in the kiln and fuse them - melt them into cabochons, which will flatten the backs out and take the sharp edges off.

I'm sure there are real fusers out there who can talk about this at great length - I just melt glass in the flame, so I'm not doing anything fancy.

If you have a collection of half beads and want to try this, here's the low-down.

Grab a kiln shelf - one may have come with your kiln, otherwise, get one from your kiln supplier, glass supplier, or a ceramics place. Make sure it fits in your kiln with room to spare. Everything gets bigger when it is hot.

Get some fibre paper, same sources as above. Cut a piece of the paper the same size as the shelf, and put it on the shelf. It probably came in a roll and wants to curl - once you have the beads in place, they will hold it down, so just weight it down for now.

Choose beads of more or less the same size, or at least, thickness. If you have super thick beads and thin together, by the time you have flatten out the fat ones, the thin ones are going to be too thin, I think. 

Make sure your bead halves are clean and dry. You can grind off the bead release that might still be on them, or leave it - if the glass is opaque and you aren't going to use them so that the back can be seen, who cares. Otherwise, remove it. Not that I was that ambitious this morning.

If you do leave bead release on them, don't have it be damp. Damp + high temps = steam = bad things in the kiln.

Arrange them on the shelf, with lots of room.

Put them in the kiln. They are really small - so you can just zoom up to full temp. Ramp up at full speed to 1600 F.

Start peeking at about 1350 degree. Open the kiln door and have a quick look.  You probably won't see any movement. You will notice it is hot and the glass is glowing.

Keep checking, every 30 - 50 degrees. You'll notice they are rounding a bit around 1420 +. Keep going until you think you like what you see. These in the picture went up to about 1480.

When they are done, you want to "crash cool" to 1000 degrees. This helps to prevent accidental devitrification.

Crash cooling consists of opening the kiln door and letting the temperature drop.

When the kiln gets down to 1000, then run a regular annealing cycle, i.e. hold at 970 for 15 mins, ramp down 100 degrees per hour to 815, hold 30 mins, ramp down 100 degrees per hour to 500, and shut off, or whatever you prefer.

You may have to open the kiln door and cool again, because as soon as you close it - the temp will climb back up. Some kiln controllers get a little upset if the temp climbs to more than 100 degrees above what they are set for, so you might see an error message. If so, just restart your annealing cycle again.

The above picture was shot at about 800 F - no glow on the glass.

I'll show you the results when they have cooled down. Too bad I didn't remember to shoot them before starting the experiment.

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