First try at bead making

Alright I bought some glass and some bead release. I had some old stainless steel rods laying around I used for mandrels.

All is good so far

I have a MAPP gas torch I was using (it is for soldering pipes not glass) I figured I would try it then invest in some more efficient equipment.

I see it is going to take some time to the the coordination between hands and judging the temperature of the glass and mandrel.

Now the problem, my green glass turned black. after I got a small bead on the mandrel I stopped and looked at the bead and it was black. So I stopped and set the mandrel down to shut off the torch and the mandrel rolled off the desk and dropped to the floor. the bead broke in half and the glass inside was green.

what was I doing wrong?

Reply to
Mark Russell
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Reply to
neoglassic

So far as described, nothing. I have some soft glass for bead work that changes color when heated. For example, I use a white that when heated is actually clear and as it cools just past the molten state it starts to turn back to opaque white.

There are also other color rods that are called strikers which change color after being heated and will remain with a different than started color after cooled.

And yes, the coordination will come with practice and time.

May I suggest a cheap way to keep the madrel from rolling away (or tools, glass rods, etc)...make a "tool rest" from a piece of metal...even a tin can with top and bottom removed then crushed flat, bend it in half to make a tent shape and then notch the top ridge with a file or hack saw. You can set the end of the madrel down and into one of the notches so it reduces the chance of hot glass rolling away out of control.

Welc, Jim

Mark Russell wrote:

Reply to
James Zapetis

Most likely your plumbing torch is burning a bit rich, so is depositing carbon on your glass. A Hothead should remedy that for the most part.

Reply to
Steve Ackman

Reply to
David Billington

He said the exterior of the bead was black while the interior (when broken) was green. IME, a color changing reduction happens throughout the glass, not just on the surface.

I've only used MAPP in a HotHead... years ago, but I suspect you're right; that the position in the flame probably is more critical with a plumbing torch.

Reply to
Steve Ackman

Reply to
Kalera

IME the reduction only effects the surface because that is all that is exposed to the reducing atmosphere. I can't think why your experience of reduction would produce an effect throughout the bulk of the glass, that sounds more like some colours which change on exposure to heat which is a bulk effect.

Reply to
David Billington

You're probably right. The only color change glass I ever worked with was clear as rod, changing to transparent orange/red as bead. I thought at the time it was due to reduction... so now that it's come up, how DOES a bulk reaction work?

Reply to
Steve Ackman

Can't answer that unfortunately, i'd like to know myself so hopefully someone who knows will come up with the information.

Reply to
David Billington

The description fits to Bullseye 1125 orange BE 1311 cranberry pink BE 1342 Cranberr sapphire and BE Erbium pink All these are clear or bluish transparent that form the color in heating.

-lauri

Reply to
Lauri Levanto

Reply to
Kalera

The mechanism of colours produced by striking is described in considerable detail in "Coloured Glasses" by W A Weyl, published by the Society of Glass Technology.

See

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and click on "Books"under "Publications" in the left hand panel.Fundamentally the colour in copper and gold ruby glasses is producedby precipitation of the metal. If you are flame working then only thesurface gets hot enough. If you bring the glass up to a more or lessuniform temperature (about 570C -600C according to Weyl's figures 91and 92) then the gold will be precipitated throughout the body of theglass.

Reply to
Terry Harper

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