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Old 03-29-2005, 06:53 PM
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Pete VanderLaan Pete VanderLaan is offline
The Old Gaffer
Join Date: Apr 2002
Location: Chocorua New Hampshire
Posts: 22,310
Pete VanderLaan is on a distinguished road
well, I still have the article and I will copy it for you. I will have to find it however but I know which room it is in. It does make a gross error in that Paul used the English and Turner numbers which have really done a very good job of standing the test of time BUT he then included the Winkelmann and Schott numbers for colorants as well. Those numbers were created for the enamelling industry and utilized an entirely different range in which to measure the expansions. They comedy of errors was compounded by Glassnotes using those numbers as well and they don't have anything to do with the real world. Simply put, there are no values for metallic oxides that are used as colorants. Industry never cared since they never planned to case colors with clear as a production item.

I really think that L.E.C. works so well for glass blowers that the viscosity issues have just about never concerned them. Not many people make the connection between viscosity and annealing ranges in thinner ware. In casting, you guys have to anneal forever , only to open the kiln and find the piece cracked which tends to make one ponder the issues at hand a good deal more. There is a lot going on. Glassblowers really get instant gratification and when things don't fit, usually you know pretty quickly. In that capacity, I don't think that Dan's observations about viscosity being the flip side of the coin will ever gain much traction. That is not the same as saying that the observations aren't correct, I think they are.

Where I think the problem lies, is in the gross generalization that such things as "96" guarantee you a clear blue sky and great sailing. I was just talking to Henry about a zinc sulphide cad sel red that is in the last edition of GlassNotes. It is a very nice red, but the L.E.C. is about 114. Cad sels really have to have at least three percent zinc in them to work well, or at least I've never seen one work with less zinc than that. That in itself is OK but if you want to make that glass color into a 96 as well, it's going to be kind of stiff to work while the clear is fairly runny. That tells me something about the likelyhood of mixing those glasses in really thick pieces as being problematic. Theyu do however work well in blown ware.

As to Mrs Manners, She and Paul long ago divorced and the last time I had heard a thing from Paul, he had quit glass and was teaching kindergarden and playing beach volleyball.. Then he vanished entirely. Anyone knowing his whereabouts, please tell me. I haven't heard a word since 1986.
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