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Reading my articles on the making of glass electrodes, you know that annealing an electrode is what makes it strong.  It makes the difference between cheap imports that crush between your fingers, and one like ours that will bounce when it falls off your workstation.

Antique and vintage electrodes are made of soda-lime, soda-lime-silicate, what we know of as standard or regular glass found in bottles and windows. No records exist to know exact compositions of glass mixtures used by any of the antique or vintage makers.  Beauty electrodes are soda-lime glass too.  The most common failure of all of these lesser quality glass electrodes is breaking of the seal inside the endcap.

The binder used and the metal endcap are stronger than the cheaper glass and twisting the electrode when inserting and removing can cause hairline fractures as the endcap forces against the glass, ‘crazing’ it inside the endcap.  This allows the gas to leak through the fractures.  If you’ve got a glass electrode that won’t light up, and you can’t see any breaks, its down in that endcap where the seal is, and it happened from twisting your electrode.

A lot of things can be done to glass to change the properties.  More alumina makes it stronger, sodium lowers the melting point so you can work with it at lower temp. Oxides in the glass make it more conductive, and adding zinc blocks UV. There was no one formula for any of the vintage makers or even any of the modern beauty makers, so its hard to know how strong your glass electrode is just by looking at it.

Boron makes glass highly stable and much stronger so we went with a borosilicate base for our external electrodes rather than soda lime. People know this type of glass as Pyrex, but the exact mix known as Pyrex is patented.

What you wind up with from electrodes, vintage and modern, is a rather broad range of differences in something that can look exactly the same.

Annealing the glass properly makes it stronger yet, and you can anneal any glass whether its soda lime or borosilicate, or the fused quartz glass that we use for our internal electrodes. What annealing does is heats the glass up to a very high temperature in a kiln, holds it, then cools it down very slowly, just a few degrees an hour. This gets rid of all internal stresses and strengthens the crystal chains. A properly annealed bead of glass should bounce.  Properly annealed electrodes like ours wont fail in their endcaps.  Their seals will not fail, and we guarantee that for life.

Why would you want to use an electrode on someone if the glass is already under stress?  Take a look at this video that shows how glass that is not annealed is already under stress.

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It would be great if you knew that the beauty electrode you just bought is weak glass or not.  You can tell by using a polarimeter, which measures optical properties.  Since glass is made stronger by strengthening the crystalline chains, a polarimeter lets you see if such chains are present.

You can also tell by subjecting it to intense heat.

Here is a user video showing one of OUR C-ring electrodes (made for kink of a special medical grade glass, and fully annealed), and comparing it to a cheap import ‘beauty’ electrode of fragile soda lime glass.  This quality is why we can give LIFETIME warranties on our glass electrodes.  Watch and see what doesn’t happen to our electrode.

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