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Old 11-30-2020, 11:44 PM
Andrew Horch Andrew Horch is offline
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COE Calculator?

I am trying to go richer in my glass colors and surprise, surprise I am having compatibility issues. Is there a good COE calculation spread sheet available at reasonable price someplace? I found these but they do not have enough additives (pigments) to be useful for color formulation:
http://glassproperties.com/expansion/
I know a generic spread sheet will not match what I am doing. I am just hoping to save a few runs when dialing things in. I am using COE96 (SP87) if that makes a difference.

I did see a the thread “Glass recipe calculator?” from 2006, but most of the links are not working. The one link that works is https://www.ilis.de/en/batchmaker.html . Is anyone using Batch Maker? I could not find a price, which is a bad sign.
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Old 12-01-2020, 07:39 AM
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Pete VanderLaan Pete VanderLaan is offline
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The basic materials are English and Turner linear expansion coefficients. They are based around a different temperature range than the coefficients from Winkleman and Schott which is why a calculation in E&T of 87 is in reality a 96.

W&S did their calculations for the enamel industry and did indeed include the metals but the range is not the same as E&T. The great mistake ws made by Paul Manners and Henry Halem in combining the two sets of calculations and treated them as one. That was in the third edition of Glassnotes. I did point out the problem to Henry and he changed it in the 4th edition.
Appen will yield you most accurate calculations and it will take some work. My spreadsheet does not provide for the additional colorants. I'm unaware of any commercial spreadsheets for doing even remotely correct calculations which play out in the real world.

In general, you should assume that anytime you make a color and go over two percent on a colorant that you are going to need to recalculate it in the studio, not at your desk. That can take years. I think I've probably spent a quarter million dollars over my lifetime messing with the issue. There's simply no substitute for melting i the pot and then testing it with Hagy seals, Ring tests and dilatometry. Thin color may work where thick color won't. Gradually you will find you need about eight different base formulas to cover the full spread of color. These were all part of my original color classes, but I'm no longer offering courses.
The other aspect is that a lot of the additives have gotten to be very difficult to get and then to use safely. Lead, Cadmium, selenium, chrome and fluorine have all come under scrutiny. In the thread on Cristalica and Reichenbach, it's easy to see that mismatch occurs by the very best. Glass is strange stuff. Remeber what I said about A,B, and C. It's very true.

But please stop calling them C.O.E. Coe of what? Linear expansion coefficient explains it better.
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Old 12-01-2020, 12:30 PM
Josh Bernbaum Josh Bernbaum is offline
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Dave Bross has been pretty sharing with the spreadsheet he made a while ago. It used to be on his davebross.com website, but looks like his website is being modified right now so I don't see the spreadsheet download there currently. I've found that the LEC on his spreadsheet calculates a bit low, but it still could be a good extra tool for you to use. I seem to get more accurate numbers from the one Pete handed out at his last class years ago, but I'll still reference Dave's at times also. There's no way around the real-world trial and error which I think Pete is alluding to. A spreadsheet won't give you all the answers to your fit problems but it can be one of the tools to help you get to a good place. You'll no doubt still have to test and adjust as you go but the spreadsheet numbers can help get us in the ballpark on paper at least. Contact Dave if you can't find a link to the spreadsheet download.
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Old 12-01-2020, 04:07 PM
Andrew Horch Andrew Horch is offline
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Maybe I was not clear. I am only hoping the spread sheet will get me closer in the beginning of the development. I am hoping it will save a few runs. I also know that people have put in a lot of work developing these sheets, which is why I said “at a reasonable price”. Let me throw out an offer. Does anyone have a good spread sheet they would be willing to give me in exchange for $100 and a promise not to resell it or give it away. I respect the work people have put into these sheets and I am willing to pay something for one. I am not expecting this to solve all my compatibility problems. It might help or it might send me down a rat hole. Whatever colors I make are for personal use only. I am concerned that even with a calculator it will still cost more time and money to develop a color than I afford.

I interested in making some glass with high sodium content and/or an opaline glass. If someone has a good recipe I can use as a base for that, I could buy that instead.
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Old 12-01-2020, 05:25 PM
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You can PM me. I have both the spreadsheet and the formula. I really dislike Sodium and hope I can convince you as to why.
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