Thread: Blue Sulphur
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Old 08-21-2019, 04:20 PM
Pete VanderLaan's Avatar
Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
 
Join Date: Apr 2002
Location: Chocorua New Hampshire
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Pete VanderLaan is on a distinguished road
So I read both Weyl and Volf on sulfur today and the blue tone is reduced to one sentence in the sulfur section of Volf. The conditions for making an acidic glass are formidable and will best happen in a phosphate which is acidic but it looks to be one of those longshots to me. I mean there are discussion of making rubies with cobalt but not in my shop.

What did impress me was looking at Strontium. Neither gives it much time when discussing phosphates and I'm not at all clear how Dave Bross came to the conclusions he did regarding replacing the calcium with Strontium, but he did it. Way to go Dave. That was good work.
At one point I suggested it to Croucher but he indicated that no one within 10,000 miles of him used it and cost would be prohibitive. Now John L is in Oakland even though John C has retired and working in his son's shop but John indicated to me recently that they had found the opalescense far denser with strontium as opposed to calcium so, again, great work.

What also strikes me in both books is that they really have the same problems that we have with a number of colorants. Silver is given a wide birth if you look to the calcedonias. Weyl does better with copper rubies than Volf does, both dance around phosphates. Many of the arguments then remain the arguments today. I remember once when John C and I were sitting around at Corning blathering with each other and John in passing said " Well I guess we proved that you certainly can melt lead crystal in an open hearth."

He was right. They used to say it couldn't be done. Had to be closed pots. Both of us think the phosphates are the last great mysteries in melts. The current boro work is really exciting and breaks so many barriers on melting cullet for color. If any of you go on with this, changing out the stabilizers is going to find you in a gold mine. I hope to spend more time on this as I find more free time from product.
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