Glass Message Board
Glass Identification - Post here for all ID requests => Glass => Topic started by: Ivo on March 11, 2007, 12:35:19 PM
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Superlight glass candlestick / Vase (the opening would just about fit a feather, having a hard time deciding which side is up) with cheerful iridescence. Anyone ran into this type of glass before?
http://glassgallery.yobunny.org.uk/displayimage.php?pos=-5580
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Ivo,
im sure ive seen something recently, checking my books whilst watching the Rugby ;)
It may have been while i was looking for stuff by Fritz Heckert, c1900.
Theres no vaseline glass in the stripes on the foot are there ???
Andy
8)
Harrach ???
http://www.great-glass.co.uk/library/lib1c.htm
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Theres no vaseline glass in the stripes on the foot are there ???
Andy
Thank you for looking. There is no vaseline and no stripes; the glass is fully transparent, optically ribbed and iridised all over. My suspicion is modern, maybe Russian...?
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Ivo,
did you check this ???
Harrach ???
http://www.great-glass.co.uk/library/lib1c.htm
I added it a bit later
Cheers
Andy
:)
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I'm assuming this is lampwork?
The Conran shop has had a lot of similar stuff recently, but not irridised. I can't find a link to the smaller pieces, candlesticks etc, but here
is a link to their lamps http://www.conranshop.co.uk/ProductDetails.aspx?pid=231923&cid=Decorative&language=en-GB
Not a great image, but the whole thing from the shade to the base is one piece of lampworked glass, presumably done a lathe, although they describe these as handblown.
I think the irridescence may be a cold spray.
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Andy: - yes I checked the Bimini items but this is not very similar; I have a good piece of Bimini to handle and the material does not feel the same.
Adam: - That is close in shape - but that lamp would be borosilicate, perhaps?
- Is there a way to tell sprayed on cold iridescence from hot??
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Yes, the Conran ones are borosilicate and presumably lampworked. If yours is super light then I would think it was lamp-worked too.
However, most people assume that borosilicate is only used for lamp-work, but it is possible to hand-blow it from the furnace.
I don't know enough about irridescence techniques, having never really used them. However, if you spray on something like Stannous Chloride, which is what most people do, while the glass is hot, you can often see a sort of crystalline structure, particularly close to the rim. I think, this is because there is a marginal degree of movement on the surface of the glass, when it is reheated, but the stannous chloride doesn't move, and therefore breaks up. However, it could also just be the nature of the stannous chloride crystals. I am not sure.
With a cold spray, which is used to give a pearlised effect on an annealed piece, the irridescence is much more like an oil on water effect.
Hope this helps. It would be easier to describe if I had two reference pieces in front of me and could point out the difference!
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I am not familiar with cold applied iridescence, but I can tell you a bit about the application of iridescence (dope) to hot glass.
Different chemical solutions may be applied: for example, stannous (tin) chloride, ferric (iron) chloride or a combination of the two. The temperature of the glass has an effect on the appearance of the resultant iridescence - a matt or satin like appearance will result if the glass is very hot, while a shinier effect will result if the glass is not quite so hot.
iridescence - http://www.geocities.com/carni_glass_uk_2000/iridescence.html
If shaping takes place after the application of iridescence it will give rise to a stretch effect. The surface of the iridescence crizzles and produces an "onion skin" look due to minute breaks occuring on the surface of the dope.
Stretch effect - http://www.geocities.com/carni_glass_uk_2000/Celeste.html
Iridescence applied to hot glass ("burnt on") is very durable and would only be removed if you damaged the actual surface of the glass itself. On the other hand, I imagine that any iridescent coating applied to a cold surface could be fairly easily removed.
Glen
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Glen, you're right about cold applied, I'm sure. We have some tumblers which were irridescent blue when we bought them. They are now totally clear glass, courtesy of the dishwasher! ::) (Luckily they were not expensive or special!) ;D
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There are modern coatings that are almost as fast as heat fused coatings.
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Does it mean I can apply iridescence from a spraycan onto anything?
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http://krylon.com/main/product_template.cfm?levelid=5&sub_levelid=8&productid=1863&content=product_details
Don't know whether it works and I wouldn't breathe it in, but go for it! :) :)
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Don't use a brillo pad on it though!
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Or a dishwasher! ::)
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I thought these Chinese borosilicate candlesticks might be interesting. :)
http://bkglass.en.alibaba.com/product/50162854/50937938/Glass_Candle_Holders/Candle_Holders/showimg.html
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Is Borosilicate usually very light, Max?
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I only really put that link here because of the mention of borosilicate, the thinness of the glass and the shape of Ivo's candlesticks - although the ones in my link aren't iridisised obviously. :) I'm not certain if borosilicate is always light, but I was thinking along the lines of test-tubes and my Pyrex thin glass lamps that are made to resist heat and could possibly be made by lampwork.
Perhaps someone could answer whether standard Pyrex oven dishes are borosilicate too...it would seem that they must be. :-\
Edit: Pyrex ovenware is soda lime glass now apparently.
http://en.wikipedia.org/wiki/Pyrex
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Usually in glass collecting terms borosilicate tends to be light, because the artists that work with it tend to be lampworkers* working on a scale that is suited to many of its properties. But those same properties are also useful for other things such as cooking and Pyrex, which is borosilicate is definitely not light.
*There are exceptions and it is possible to blow borosilicate straight from the furnace.
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Thanks, I am assuming though that the little light light phials that Bimini made would have been soda?
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Thanks everybody for rekindling the discussion. As far as I know Bimini is soda glass. Part of that production was made at Venini's where sodaglass is standard.
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The Borosilicate used by lampworkers only came into use in the 1990's. Moncrieff were mainly manufacturing with borosilicate glass and much was handblown.
These items are NOT lightweight http://www.ysartglass.com/Moncrieff/Moncriefflab1.htm
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Goodness, you wouldn;t want to drop one of those dessicators on your foot!
:o