Topic: Pyrex???

[sonjajoyce]

Hi

Hope someone can help me - My Uncle used to work for 'Pyrex' as it is now many many years ago and part of their apprentice pieces was to make 'passion spirals' - I am desperatelylooking for one of these now and was wondering if anyone knew where I might find one.
Thanks

[Frank]

They sound intriguing  do you have a description of them?

Pyrex was a brand that was made in various countries by different companies, which country is relevant here?

[David E]

I would assume England, judging by Sonja's BT e-mail address (oh, and welcome to GMB!)

If so, then this would be James A Jobling.

Not sure, Frank, but wasn't Pyrex a brandname solely for the UK market? I think Cornings (the licensees) used a different brandname and a French license holder another name. I'll dig about and see what surfaces...

Edit: nope

http://en.wikipedia.org/wiki/Pyrex

[Frank]

Don't expect too much from that Wikipedia article, whoever authored has not been very thorough and it could be misleading. Particulary on safety of boro-silicate which will also crack if placed on an open flame (from experience as a kid). I was shocked to read of the switch to soda-lime - it is just a way of cutting cost but at the same time compromising safety. Labelling that as Pyrex which capabilities are generally known is bordering on criminal. If they did that in Europe they would probably be obliged to put a notice warning it is not to be used for cooking. So as ever, never treat Wikipedia as a quality source of reference, it is useful as a starting point but by its nature the contents are readily manipulated and not academic quality.

Also to be accurate Pyrex is one form of boro-silicate glass with the main difference to other formulations being the amount of aluminium included in the metal. Boro-silicate glass was probably first made in Italy circa 1600 and likely before that too. The original Pyrex cookware was targeted mostly at catering use and to make more attractive styles for home use the formulation was changed to allow thinner pieces to be made. There is an excellent account of Pyrex by Jobling in the Mixed Batch magazine reproduced in the Glass-Study.

[David E]

I remember my mother accidentally putting a plate on top of a warm electric ring, which proceeded to blow up into a zillion pieces. BTW, I have had cause to edit that Wiki article to get the dates right. I agree about its editorial quality.

I did read somewhere that borosilicate-based glass could date back to Roman times, but wasn't sure if that was a flight of fancy.

Lastly, I am thinking that Adam Dodds might be able to help on this one, as he did work at Jobling for eleven years.

[Frank]

Yes Adam might know about the passion spirals, which is the main topic 

There is a recipe for Borosilcate in L'Arte Vetraria by Antonio Neri. If anyone has a copy of that, preferably one of the English translations (or both) by Christopher Merrit "The Art of Glass..." (long title) I would like to copy it for the Glass-Study 

Common story is that Corning invented Pyrex c1920 by adding Alumina but I have 19th century recipes including it.

[David E]

Common story is that Corning invented Pyrex c1920 by adding Alumina but I have 19th century recipes including it.

1915 - but "redeveloped" might be more accurate. Anyway, "passion spirals"... :spls2:

[Adam]

Let's get the main topic out of the way first.  Sorry, I haven't a clue as to what a passion spiral might be, although my mind is boggling a little as to what it might be used for!  Unless things changed dramatically after 1972 (usual disclaimer - I know nothing about Jobling after that) friggers out of the main furnace would be unlikely - conditions were not right.  The laboratory ware department, however, had a number of superbly skilled lampworkers who could and often did make amazing things.  End of my knowledge on that one.

"Pyrex" Brand (and we would have been strung up if we ever dared to write just Pyrex or, worse, pyrex) was a brand name and not a glass composition.  "Pyrex" laboratory ware had to be borosilicate because it was marketed as having a very specific coefficient of expansion (33.0 plus or minus 1.0 cm/cm/degree C if you must know!).  "Oven-to-table" ware was marketed as just oven to table ware.  The clear stuff was, of course, borosilicate, although most of it was a slightly easier to press version with an expansion of, I think, around 35.

 However, Frank, "Pyrex" opal oven-to table ware was more or less a soda-lime composition - not straightforward, of course, being opal.  It was given its resistance to thermal shock by being tempered.  We used the word tempered to indicate a similar process to, but less severe than, toughened car side windows.  The degree of temper was designed to make the resistance to thermal shock equivalent to that of annealed borosilicate.  Just to complicate things, for production reasons (therefore not publicised) a lot of the borosilicate production was also slightly tempered rather than annealed, which gave it an even higher resistance to shock.

"Pyrex" domestic stuff was ovenware, NOT top of stove.  There may be some confusion here.  Jobling sold, but didn't make, "Pyrosil" brand which was a glass-ceramic.  This would stand anything thermal shock-wise.  A party trick, used in stores at its introduction I believe was to heat it red hot with a blowlamp and drop it into iced water.

I could go on a lot further but I'll spare you.  One of my jobs as Technical Services manager was to knock all this and more into new sales reps in, I think, half a day.  I doubt if much of it stuck!!

Adam D.

[Frank]

Let's get the main topic out of the way first.  Sorry, I haven't a clue as to what a passion spiral might be, although my mind is boggling a little as to what it might be used for!

Indeed Adam 

The rest was off the top of my head having read a lot of different accounts so not to surprising I got a little muddled there 


Sonjajoyce - what was the time period that your uncle trained?

[Heidimin]

There was a book on British Pyrex published last year: Little Book of Collectable British Pyrex by Susan Hibbard. According to the blurb:

Susan Hibberd owns hundreds of pieces of Pyrex glassware and Pyrex-related collectables and she shares them with you in this exciting new book.

 PYREX was patented in America in 1915 and was produced in Sunderland between 1921 and 1973 by James A. Jobling. Having been made only during this period it is becoming increasingly rare and collectable.

‘The Little Book of Collectable British Pyrex’ tells you everything you need to know about the production methods and design of PYREX glassware, as well as giving you an insight into what it was like to work in the factory.

On flame-resistance, US Pyrex had a range called Flameware, which included saucepans, teapots and coffee percolators, and was marketed from 1936 to 1979. And I know it's flame-resistant, because I make my porridge in one every morning. (And my tea at work in a Flameware teapot.) Plenty of it about on US e-bay, but I don't know whether it was ever sold in the UK, or whether my two pieces found their way here in somebody's household goods. There's a 70s-looking amber-coloured saucepan that comes up regularly on UK e-bay listed as Pyrex - would that be Pyrosil, Adam?