[Steppes] Roman Standards

Tue Feb 3 23:00:20 PST 2009

the glory hole was a fifty gallon drum refractory bricks and refractory 
blanket-about 4" of thickness, two venturi burners, I can't remember the 
btu but we ran them on natural gas cause the college had a producing 
well.  The melting kiln (for loss of a special name for it) was all hard 
refractory brick and a single burner was sufficient-- I'd have to go 
back and refresh the specifics to tell the truth,  it was @ 1986-88 when 
we did it...   we didn't make the glass-- nasty fumes and city 
ordinances... 

space for the equip would be the primary supply

dominic barranco wrote:
> so ya say we're setting up a glass works...cool I'm all for it.   What 
> supplys do we need.
>  
> Damon Xanthu ( who is not really kidding)
>
> ------------------------------------------------------------------------
> *From:* uilliacc <uilliacc at gmail.com>
> *To:* AlKudsi at aol.com; Steppes List <Steppes at lists.ansteorra.org>
> *Sent:* Tuesday, February 3, 2009 6:34:20 PM
> *Subject:* Re: [Steppes] Roman Standards
>
> I was referring to the objects pictured with the article-- I don't 
> think they were blown...
>
> As to the brittleness of ancient glass-
> blown glass becomes brittle when cooled too fast-- in "modern" glass 
> blowing they learned to make it more durable by cooling slow in an 
> annealing oven.  The cause of the brittleness is linked to locking in 
> the less defined more haphazard crystaline structures. Annealing 
> allows the glass structure to relax and realign more slowly into a 
> less internally stressed crystaline structure.  Kinda like making 
> diamonds or making quartz**
>
> blowing glass is popular for making containers-- whether it's into a 
> mold or not--  this particular object isn't meant to contain anything...
>
> as to working or grinding glass
> lower temp lump glass tends to be soft rather than brittle---higher 
> levels of flux are used to lower the melting point--
>
> glass can also be poured or pressed into a mold, or worked like beads 
> - the result would be solid (more survivable than blown glass)--  if 
> semi-round it could easily be hand worked into a sphere-- not much 
> overworking there (besides heating/cooling of the glass is the problem 
> resulting in brittleness)-- also dropping viscous glass into a 
> tempering fluid (oil) slowing its cooling rate produces strong well 
> structured glass in spheric drops much like making shot-- again if 
> it's mostly round to begin with not much "grinding" required-- more 
> like sanding.  I based my suggestion on the pictures of the actual 
> object it does not appear to be hollow. when in doubt K.I.S.S. is 
> usually right.  you get green with copper carbonate, but any copper 
> presence in glass making process would likely lean it towards green
>
> **by the way as an undergraduate we spent a summer building a glass 
> blowing workshop from scratch, the annealing oven was the one part 
> that we couldn't get right-- washing machine  timers and  oven 
> elements didn't work, well but the glory hole and melting furnace 
> worked fine many fine shapes were blown, few survived the cool down...
>
> in addition to glasswork (sandblast etched, foiled, leaded and grouted 
> stain glass), there's several years practical experience in glaze 
> formation, kiln building and maintenance(a wood fired, raku and a 
> large gas bag wall "walk in" as well as electric), and brazed and 
> welded metal work(I'm fascinated with the transformative properties of 
> fire). There jewelry work including lapidary.--
> I guess I should have learned something in 10 years as a full time 
> undergrad... four great instructors at a small regional Ok school... 
> priceless...
>
> uillecc
>
>
> AlKudsi at aol.com <mailto:AlKudsi at aol.com> wrote:
> > I was basing my speculation on the fact that glass blowing into a 
> mold was very popular with the Romans. Although the story was talking 
> about the other standard being made out of chalcedony, that is a 
> relatively easy stone to grind into a sphere (and polish) because it 
> is just hard enough to work (7 on the Mohs scale) but has no clevage 
> points. Most glass of the period, according to some sources, was a bit 
> brittle if overworked, which you'd have to do to grind it, and didn't 
> take on a polished finish easily. Man-created glass at that time was 
> much more likely to be blown into a mold if you wanted it polished. It 
> is true that if it were volcanic glass (obsidian), or glass formed 
> from impact meteorites (such as Moldavite), it would constitute a 
> "star stone" and probably be ground. However, it would probably take 
> an expert to determine just how the glass was worked.
> >  Yes, glass has a much older tradition than blown glass...faience, 
> used by the Egyptians since about 1500 BC is a form of glass that is 
> then ground, made into a paste with traces of copper to make it blue 
> or blue-green and made into a glaze for pottery by refiring. But the 
> oldest known BLOWN glass, according to most sources, is about 50 BC 
> Phoenicia. Glass can be worked in so many ways, though...as a glaze, 
> as pulled, as blown, as ground, as molded, and as tumbled.
> >  Sorry, new area of interest: minerals and gemstones, and by 
> default, things such as opal and glass which are technically not 
> minerals, but mineraloids because they do not have a regularly ordered 
> internal structure.
> >  HL Saqra
> > quoting some from the Smithsonian book: _Rock and Gem: The 
> Definitive Guide to Rocks, Minerals, Gems, and Fossils_, as well as 
> some research in my pottery sources.
>
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