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What are Furnace Beads?

These are pics of pulling the cane to make glass furnace beads or cane beads.

They're odds and ends of pics from 2003, 04 and 05.

The basic idea is to make a cane with a hole in the center then cut it into bead size pieces which are finished out by tumbling.

Murrine are done the same way but without the extra required to put a hole in the middle or tumble finish. You're designing murrine for what you'll eventually see in cross section.

Murrini and the canes they were cut from.

Murrini glass canes and cut murrini

OK, Here we Go...Let's Make Some Furnace Beads

Gathering the white glass from a small crucible full of hot white glass that is sitting in the back of the glory hole underneath the hatch I'm lifting with my left hand. I just dipped the blowpipe into a pot of white glass and I'm letting the extra drip back into the pot. This will be the white core of the furnace beads.

Gathering white core of glass furnace bead

Closing the hatch in the glory hole as the white glass cools a bit. I'll take one or two more gathers of the white glass..

Cooling the furnace bead core

Marvering it out, which is smoothing and shaping the glass on a steel plate by rolling the gather of glass back and forth on the steel.

Marvering the glass furnace bead core

After re-heating the white glass in the glory hole (glowing hot device in front of me in the pic) I blow a bubble into the gather of glass. The bubble eventually becomes the hole in the middle of the bead.

Blowing out furnace bead gather

Dipping the white glass with the bubble in the middle into a pot full of hot colored glass in one of the glass furnaces.

Gathering the color glass for furnace beads

"Tailing off" the colored glass, or letting the extra hot glass drip back into the furnace while you spin the gather of glass.

Tailing off the glass gather

Back to the marver, where we shape up the colored glass we just picked up on top of the white glass.

Marvering the glass color for furnace beads

This is one way you could put a ribbed texture on the outside of a gather. That texture would stay there even when the cane is pulled out and will be there in the finished furnace bead.

Putting texture into furnace beads

If you wanted square furnace beads you would start with a square gather. This one is not quite shaped up yet but you get the idea. You can control the shape of the finished furnace bead by shaping the gather into a square, triangle, etc.

Squaring the gather for square furnace beads

The glass gather has to be kept hot, and at the same heat throughout. This means a lot of reheating it in the glory hole and marvering to keep it in shape and cool the exterior until internal and external heat are close to the same.

Reheating glass gather for furnace beads

Reheating the glass gather looking from another angle.

Reheating glass

The tip of the gather of hot glass is cooled by dipping it in water to harden it. This hardened part is clamped in a homemade tool to hold it and then the cane is pulled out. You can see the tool opened up in the pics up above.

Pulling furnace glass bead cane - same process as murrine, just no hole

A close up of the tool

 glass tool for holding end of cane

The first cut, cutting the cane from what's left of the gather on the blowpipe.

Cutting bead glass cane

Cutting up the rest of the cane. The wooden cradle holds the cane so it's easier to put it into the annealer. An annealer is something like the kiln you'll see in a minute. This bring the temperature of the glass down to room temperature very slowly. This is necessary to relieve all the strains in the glass.

Cutting glass furnace bead glass cane smaller to fit kiln/annealer

Shoveling the canes into the kiln/annealer

furnace bead canes go into the kiln/annealer

Straightening out canes. It's a bit over 900 degrees F. in there so you have to be quick.

Straightening out the glass furnace bead glass canes in the kiln/annealer

All set! Ready to close the door and let them anneal.

Furnace bead glass canes in the kiln/annealer

After the canes are annealed and cooled down they're cut into individual furnace beads on a lapidary saw .

Cutting furnace bead glass canes on the diamond saw

The final step is tumbling the rough cut furnace glass beads in a rock tumbler using a series of decreasing grit size abrasives to round and polish them. This takes many days, which is one of the reasons furnace beads are expensive.

Tumbling furnace beads in a rock tumbler to finish and polish