Posted on December 01 2017


Thomas Grimmett


New Color, Product News, Video

Antidote, Tested Compatible

Antidote, Tested Compatible


Hey guys. I’m Thomas Grimmett from Glass Alchemy.
Today I want to talk to you about our latest color called Antidote and the science behind our new pastel palette.

It’s always been a long-term goal of mine to develop a pastel palette, somewhere between transparent and not quite fully opaque.  I talk to a lot of artists and it sounds like there’s a big need out there for reliable, workable pastel colors.

Antidote is the first color in our new line.  It is available now and I want to demonstrate its compatibility, so you can see why I am so excited.

When you make a color, you are adding colorants and chemicals with different viscosities and Co-efficient of Thermal Expansion.  My end goal as a glassmaker is to make a compatible, highly workable color.  

I’m going to show you how I test our glass for compatibility, using a trident seal.  Developed by an engineer at Corning in the 70s, it is a glass-to-glass seal that is used to measure the expansion differential between two different glasses.

I have a rod of 4mm in my hands that we are looking at under the polarimeter.  You can see when it’s nice and straight and I’m not adding any tension or compression to it, the rod looks pretty much clear.  Im going to start to flex the rod a little bit to get an idea of what glass looks like under stress.  You can start to see that dark band developing.

Pay close attention to how it looks right before the snapping point.  It is going to snap. 

I made a trident seal that is all clear, basically it is clear welded to clear.  And that’s what will serve as our control group.

Both trident seals will go in the oven for a proper anneal cycle.  When they are cool, we will take them out and look at them under the polarimeter.

By looking at a trident seal under a polarimeter, it will show us the residual stress remaining after annealing.  At GA, we strive for the compatibility to be as close to clear as possible.

Let’s take a look.

What this test shows me is that working Antidote is very close to working clear from a Co-efficient of Thermal Expansion standpoint.

Now, for comparison sake, I want to show you some glass from different manufacturer.  As you can see, this color responds much differently to clear under the polarimeter. 

This trident seal here is the Antidote, with Simax down the middle, this seal here is all Simax, Simax down the middle, Simax on both sides.

This other glass over here is Simax down the middle and let’s call it a mystery green for the sake of this video.

Now, if you remember the example I showed you earlier of what stressed out glass looked like right before it breaks, you will notice some similarities between that and what we are looking at here.

The bottom line is that all glassmakers have the ability to check their glass for compatibility.  Here at GA, we check every batch of glass that we make.

We are excited about Antidote and we hope you are too.

Stay tuned for more great pastel colors coming from Glass Alchemy…




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